// ----------------------------------------------------------------------
// 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 Aug 2004: have tested that IE 5.0 and IE 5.5 both support DOM model
// sufficiently well, so innerHTML option removed (redundant).
//
// 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
// ----------------------------------------------------------------------

var nbsp = 160;    // non-breaking space char
var node_text = 3; // DOM text node-type
var emptyString = /^\s*$/ /* \s Matches any whitespace character; /^ start a regular expression; $/ end of a regular expression*/
var glb_vfld;      // retain vfld for timer thread

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

function trim(str)
{
  return str.replace(/^\s+|\s+$/g, '');/* object.replace(regexp, newSubStr) method is used to match a specifed regular expression against a string and replace any match with a new substring.*/
}


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

function setFocusDelayed()
{
  glb_vfld.focus()
}

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

// -----------------------------------------
//            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)
// -----------------------------------------

var proceed = 2;  

function commonCheck    (vfld,   // element to be validated
                         reqd)   // true if required
{
  if (!document.getElementById) 
    return true;  // not available on this browser - leave validation to the server

  if (emptyString.test(vfld.value)) {
    if (reqd) {
      setfocus(vfld);
      return false;
    }
    else {
      return true;  
    }
  }
  return proceed;
}

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

function validatePresent(vfld)
{
  var stat = commonCheck (vfld, true);
  if (stat != proceed) return stat;

  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  (vfld,   // element to be validated
                         reqd)   // true if required
{
  var stat = commonCheck (vfld, reqd);
  if (stat != proceed) return stat;

  var tfld = trim(vfld.value);  // value of field with whitespace trimmed off
  var email = /^[^@]+@[^@.]+\.[^@]*\w\w$/
  if (!email.test(tfld)) {
    alert("ERROR: not a valid e-mail address");
    setfocus(vfld);
    return false;
  }

  var email2 = /^[A-Za-z][\w.-]+@\w[\w.-]+\.[\w.-]*[A-Za-z][A-Za-z]$/
  if (!email2.test(tfld)) 
   alert("Unusual e-mail address - check if correct");
  return true;
};

// -----------------------------------------
//             compareEmails
// check email and re_email fields if it empty or not
// if it's not empty then
// Compare two address emails
// Returns true if OK 
// -----------------------------------------

function compareEmails	(re_email, email)  
{
	if (emptyString.test(email.value) || emptyString.test(re_email.value))
	{
   	 	return false;
	} 
	else
	{
		if (email.value != re_email.value)
		{
			alert("ERROR: Your email addresses don't match. Please double check");
   	 		return false;
		}
		else 
		{
			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  (vfld,   // element to be validated
                         reqd)   // true if required
{
  var stat = commonCheck (vfld, reqd);
  if (stat != proceed) return stat;

  var tfld = trim(vfld.value);  // value of field with whitespace trimmed off
  var telnr = /^\+?[0-9 ()-]+[0-9]$/
  if (!telnr.test(tfld)) {
   alert("ERROR: not a valid telephone number. Characters permitted are digits, space ()- and leading +");
    setfocus(vfld);
    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) {
    alert("ERROR: " + numdigits + " digits - too short");
    setfocus(vfld);
    return false;
  }

  if (numdigits>14)
    alert(numdigits + " digits - check if correct");
  else { 
    if (numdigits<10)
     alert("Only " + numdigits + " digits - check if correct");
  }
  return true;
};