// ----------------------------------------------------------------------
// Javascript form validation routines.
// Author: Stephen Poley
//
// Simple routines to quickly pick up obvious typos.
// All validation routines return true if executed by an older browser:
// in this case validation must be left to the server.
//
// Update Jun 2005: discovered that reason IE wasn't setting focus was
// due to an IE timing bug. Added 0.1 sec delay to fix.
//
// Update Oct 2005: minor tidy-up: unused parameter removed
//
// Update Jun 2006: minor improvements to variable names and layout
// ----------------------------------------------------------------------

var nbsp = 160;		// non-breaking space char
var node_text = 3;	// DOM text node-type
var emptyString = /^\s*$/ ;
var global_valfield;	// retain valfield for timer thread

// --------------------------------------------
//                  trim
// Trim leading/trailing whitespace off string
// --------------------------------------------

function trim(str)
{
  return str.replace(/^\s+|\s+$/g, '');
}


// --------------------------------------------
//                  setfocus
// Delayed focus setting to get around IE bug
// --------------------------------------------

function setFocusDelayed()
{
  global_valfield.focus();
}

function setfocus(valfield)
{
  // save valfield in global variable so value retained when routine exits
  global_valfield = valfield;
  setTimeout( 'setFocusDelayed()', 100 );
}


// --------------------------------------------
//                  msg
// Display warn/error message in HTML element.
// commonCheck routine must have previously been called
// zrw : rearranged so only message is required
// --------------------------------------------

function msg(message, // string to display
             fld,     // id of element to display message in
             msgtype) // class to give element ("warn" or "error")              
{
  // setting an empty string can give problems if later set to a 
  // non-empty string, so ensure a space present. (For Mozilla and Opera one could 
  // simply use a space, but IE demands something more, like a non-breaking space.)
  var dispmessage;
  if (emptyString.test(message)) 
    dispmessage = String.fromCharCode(nbsp);    
  else  
    dispmessage = message;

  if (fld===undefined)
    alert(message);
  else
  {
      var elem = document.getElementById(fld);
      elem.firstChild.nodeValue = dispmessage;  
      if (msgtype!==undefined)
        elem.className = msgtype;   // set the CSS class to adjust appearance of message
  }  
}

// --------------------------------------------
//            commonCheck
// Common code for all validation routines to:
// (a) check for older / less-equipped browsers
// (b) check if empty fields are required
// Returns true (validation passed), 
//         false (validation failed) or 
//         proceed (don't know yet)
// zrw: allow for only passing in valfield
// enable hidding/showing element
// --------------------------------------------

var proceed = 2;  

function commonCheck    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required, hideID, hidePair, message)   // true if required
{
  if (!document.getElementById) 
    return true;  // not available on this browser - leave validation to the server
  var elem = document.getElementById(infofield);
  if (!elem.firstChild) return true;  // not available on this browser 
  if (elem.firstChild.nodeType != node_text) return true;  // infofield is wrong type of node  

  if (emptyString.test(valfield.value)) {
    if (required) {
      if (message == undefined) message = '*';
      msg (message, infofield, "error");  
      //setfocus(valfield);
      if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";    
      return false;
    }
    else {
      msg ("", infofield, "warn");   // OK
      if (hideID!==undefined && hideID !== false)
      {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
      }
      return true;  
    }
  }
  return proceed;
}

// --------------------------------------------
//            validatePresent
// Validate if something has been entered
// Returns true if so 
// --------------------------------------------

function validatePresent(valfield,   // element to be validated
                         infofield, hideID, hidePair, message) // id of element to receive info/error msg
{
if (hidePair===undefined || hidePair===false)
    hidePair = true;
  var stat = commonCheck (valfield, infofield, true, hideID, hidePair, message);
  if (stat != proceed) return stat;
  if (hideID!==undefined && hideID !== false)
      {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
      }
  msg ("", infofield, "warn");  
  return true;
}

// --------------------------------------------
//            validatePassword
// Validate for "secure" passwords
// Returns true if so 
// --------------------------------------------

function validatePassword(valfield,   // element to be validated
                         infofield, hideID, hidePair) // id of element to receive info/error msg
{
if (hidePair===undefined || hidePair===false)
    hidePair = true;
  var stat = commonCheck (valfield, infofield, true, hideID);
  if (stat != proceed) return stat;
  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  var allAlpha = /^[A-Za-z]*$/  ;
  if (tfld.length < 6 || tfld.length > 15 || allAlpha.test(tfld))
  {
    msg ("Password must be 6-15 characters and must contain at least one number or special character", infofield, "error");
    //setfocus(valfield);
    if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";    
    return false;
  }
  else
    msg ("", infofield, "warn");
  if (hideID!==undefined && hideID !== false)
  {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
  }
  return true;
}

// --------------------------------------------
//            validateTextLength
// --------------------------------------------

function validateTextLength(valfield,   // element to be validated
                         minlength, maxlength, infofield, hideID, hidePair) // id of element to receive info/error msg
{
if (hidePair===undefined || hidePair===false)
    hidePair = true;
  var stat = commonCheck (valfield, infofield, true, hideID);
  if (stat != proceed) return stat;
  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  if (tfld.length < minlength || tfld.length > maxlength)
  {
    msg ("A minimum of " + minlength + " and a maximum of " + maxlength + " characters are allowed.", infofield, "error");
    //setfocus(valfield);
    if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";    
    return false;
  }
  else
    msg ("", infofield, "warn");
  if (hideID!==undefined && hideID !== false)
  {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
  }
  return true;
}

// --------------------------------------------
//            validateMatch
// --------------------------------------------

function validateMatch(valfield,matchfield,   // element to be validated
                         infofield, required, hideID, hidePair) // id of element to receive info/error msg
{
if (hidePair===undefined || hidePair===false)
    hidePair = true;
  var stat = commonCheck (valfield, infofield, required, hideID);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  if (valfield.value!=matchfield.value && matchfield.value.length > 0) 
  {
    msg ("Passwords must match", infofield, "error");
    //setfocus(valfield);
    if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";    
    return false;
  }
  else
    msg ("", infofield, "warn");
  if (hideID!==undefined && hideID !== false)
  {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
  }
  return true;
}

// --------------------------------------------
//               validateEmail
// Validate if e-mail address
// Returns true if so (and also if could not be executed because of old browser)
// --------------------------------------------

function validateEmail  (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required, hideID, hidePair)   // true if required
{
if (hidePair===undefined || hidePair===false)
    hidePair = true;
  var stat = commonCheck (valfield, infofield, required, hideID);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  var email = /^[^@]+@[^@.]+\.[^@]*\w\w$/  ;
  if (!email.test(tfld)) {
    msg ("Invalid e-mail address", infofield, "error");
    //setfocus(valfield);
    if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";    
    return false;
  }
  
  var email2 = /^[A-Za-z][\w.-]+@\w[\w.-]+\.[\w.-]*[A-Za-z][A-Za-z]$/  ;
  if (!email2.test(tfld)) 
    msg ("Unusual e-mail address - check if correct", infofield, "warn");
  else
    msg ("", infofield, "warn");
  if (hideID!==undefined && hideID !== false)
  {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
  }
  return true;
}

// --------------------------------------------
//               validateUrl
// Validate if internet url
// Returns true if so (and also if could not be executed because of old browser)
// --------------------------------------------

function validateUrl  (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required, hideID, hidePair)   // true if required
{
  if (hidePair===undefined || hidePair===false)
    hidePair = true;
  var stat = commonCheck (valfield, infofield, required, hideID,hidePair);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  var url = /^([\w-]+\.)+[\w-]+(\/[\w- .\/?%&=]*)?$/  ;  
  if (!url.test(tfld)) {
    msg ("Invalid url", infofield, "error");
    //setfocus(valfield);
    if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";
    return false;
  }  
  if (hideID!==undefined && hideID !== false)
  {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
  }
  msg ("", infofield, "warn");
  return true;
}

// --------------------------------------------
//               validateWebsite
// Validate if internet site (no pages)
// Returns true if so (and also if could not be executed because of old browser)
// --------------------------------------------

function validateWebsite  (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required, hideID, hidePair)   // true if required
{
  if (hidePair===undefined || hidePair===false)
    hidePair = true;
  var stat = commonCheck (valfield, infofield, required, hideID,hidePair);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  var site = /^([\w-]+\.)+[\w-]+$/  ;  
  if (!site.test(tfld)) {
    msg ("Invalid site name", infofield, "error");
    //setfocus(valfield);
    if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";
    return false;
  }  
  if (hideID!==undefined && hideID !== false)
  {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
  }
  msg ("", infofield, "warn");
  return true;
}



// --------------------------------------------
//            validateTelnr
// Validate telephone number
// Returns true if so (and also if could not be executed because of old browser)
// Permits spaces, hyphens, brackets and leading +
// --------------------------------------------

function validateTelnr  (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required, hideID, hidePair)   // true if required
{
if (hidePair===undefined || hidePair===false)
    hidePair = true;
  var stat = commonCheck (valfield, infofield, required, hideID);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  var telnr = /^\+?[0-9 ()-]+[0-9]$/  ;
  if (!telnr.test(tfld)) {
    msg ("Invalid telephone number", infofield, "error");
    //setfocus(valfield);
    if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";
    return false;
  }

  var numdigits = 0;
  for (var j=0; j<tfld.length; j++)
    if (tfld.charAt(j)>='0' && tfld.charAt(j)<='9') numdigits++;

  if (numdigits<6) {
    msg ("Only " + numdigits + " digits - too short", infofield, "error");
    //setfocus(valfield);
    if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";
    return false;
  }

  if (numdigits>14)
    msg (numdigits + " digits - check if correct", infofield, "warn");
  else { 
    if (numdigits<10)
      msg ("Only " + numdigits + " digits - check if correct", infofield, "warn");
    else
      msg ("", infofield, "warn");
  }
  if (hideID!==undefined && hideID !== false)
  {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
  }
  return true;
}

// --------------------------------------------
//             validateInt
// Validate person's age
// Returns true if OK 
// --------------------------------------------

function validateInt    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required,  // true if required
                         low, high, hideID, hidePair)   
{
if (hidePair===undefined || hidePair===false)
    hidePair = true;
  var stat = commonCheck (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);
  var ageRE = /^[0-9]{1,3}$/
  if (!ageRE.test(tfld)) {
    msg ("Not a valid number", infofield, "error");
    //setfocus(valfield);
    if (hideID!==undefined && hideID !== false)
        document.getElementById(hideID).style.visibility = "hidden";
    return false;
  }

  if (tfld>high || tfld < low) {
    msg ("Enter a value between " + low + " and " + high + ".", infofield, "error");
    setfocus(valfield);
    return false;
  }
  if (hideID!==undefined && hideID !== false)
  {
      if (hidePair)
        document.getElementById(hideID).style.visibility  = "visible";
      else
        document.getElementById(hideID).style.visibility = "hidden";        
  }

  return true;
}