// ----------------------------------------------------------------------
// 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.
// ----------------------------------------------------------------------

var nbsp = 160;    // non-breaking space char
var node_text = 3; // DOM text node-type
var emptyString = /^\s*$/
var glb_vfld;      // retain vfld 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(vfld)
{
  glb_vfld.focus()
}

function setfocus(vfld)
{
  glb_vfld = vfld;
  setTimeout( 'setFocusDelayed()', 100 );
}


// -----------------------------------------
//                  msg
// Display warn/error message in HTML element
// commonCheck routine must have previously been called
// -----------------------------------------

function msg(fld,		// id of element to display message in
             msgtype,	// class to give element ("warn" or "error")
             message)	// string to display
{
  // 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;

  var elem = document.getElementById(fld);
  elem.firstChild.nodeValue = dispmessage;  
  
  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)
// -----------------------------------------

var proceed = 2;  

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

  if (emptyString.test(vfld.value)) {
    if (reqd) {
      msg (ifld, "error", "ERROR: required");  
      setfocus(vfld);
      return false;
    }
    else {
      msg (ifld, "warn", "");   // OK
      return true;  
    }
  }
  return proceed;
}

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

function validatePresent(vfld,   // element to be validated
                         ifld )  // id of element to receive info/error msg
{
  var stat = commonCheck (vfld, ifld, true);
  if (stat != proceed) return stat;

  msg (ifld, "warn", "");  
  return true;
};


function validateLength(vfld,
						ifld,
						minimum,
						maximum)
{
	var stat = commonCheck(vfld,ifld,true);
	if(stat != proceed) return stat;
	
	var tfld = trim(vfld.value);
	if(tfld.length < minimum) {
		msg(ifld,"error","ERROR: Must be at least "+minimum+" characters");
		setfocus(vfld);
		return false;
	}
	if(tfld.length > maximum) {
		msg(ifld,"error","ERROR: Must be less than "+maximum+" characters");
		setfocus(vfld);
		return false;
	}
	else
		msg(ifld,"warn","");
	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
                         ifld,   // id of element to receive info/error msg
                         reqd)   // true if required
{
  var stat = commonCheck (vfld, ifld, 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)) {
    msg (ifld, "error", "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)) 
    msg (ifld, "warn", "Unusual e-mail address - check if correct");
  else
    msg (ifld, "warn", "");
  return true;
};

function validateAlphaNumeric (vfld,	//element to be validated
							   ifld,	//id of element to receive info/error msg
							   reqd)	//true if required
{
		var stat = commonCheck (vfld, ifld, reqd);
		if (stat != proceed) return stat;
		
		var tfld = trim(vfld.value);	//value of field with whitespace trimmed off
		var alphanumeric = /^([a-zA-Z0-9_\-\.]){4,}$/
		if (!alphanumeric.test(tfld)) {
			msg(ifld, "error", "ERROR: see description above");
			setfocus(vfld);
			return false;
		}
		else {
			msg (ifld,"warn","");
			return true;
		}
};


function validateNumeric (vfld,	//element to be validated
							   ifld,	//id of element to receive info/error msg
							   reqd)	//true if required
{
		var stat = commonCheck (vfld, ifld, reqd);
		if (stat != proceed) return stat;
		
		var tfld = trim(vfld.value);	//value of field with whitespace trimmed off
		var numeric = /^([0-9_\-\.]){4,}$/
		if (!numeric.test(tfld)) {
			msg(ifld, "error", "ERROR: see description above");
			setfocus(vfld);
			return false;
		}
		else {
			msg (ifld,"warn","");
			return true;
		}
};


function validatePhone (vfld,	//element to be validated
							   ifld,	//id of element to receive info/error msg
							   reqd)	//true if required
{
		var stat = commonCheck (vfld, ifld, reqd);
		if (stat != proceed) return stat;
		
		var tfld = trim(vfld.value);	//value of field with whitespace trimmed off
		var banned = /^(555|111|000)|^([0-9]{3}(555|111|000))/
		if (!validateNumeric(vfld,ifld,reqd)) {
			return false;
		}
		else if (!validateLength(vfld,ifld,10,10)) {
			return false;
		}
		else if (banned.test(tfld)) {
			msg(ifld,"error","ERROR: Not a valid phone number");
			setfocus(vfld);
			return false;
		}
		else {
			msg (ifld,"warn","");
			return true;
		}
};


function validatePass(vfld1,
				   vfld2,
				   ifld1,
				   ifld2)
{
	var tfld1 = trim(vfld1.value);
	var tfld2 = trim(vfld2.value);

	if (tfld1 != tfld2)
	{
		msg(ifld1, "error", "ERROR: do not match");
		msg(ifld2, "error", "ERROR: do not match");
		return false;
	}
	else
	{
		var errs = 0;
		if(commonCheck(vfld1,ifld1,true) != proceed) errs += 1;
		if(commonCheck(vfld2,ifld2,true) != proceed) errs += 1;
		if(errs > 0) return false;
	}
	msg(ifld1, "warn", "");
	msg(ifld2, "warn", "");
	return true;
};