// validation
// ----------------------------------------------------------------------
// 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
// --------------------------------------------

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    (valfield,   // element to be validated
infofield,  // id of element to receive info/error msg
required)   // 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) {
			msg (infofield, "error", "Required");
			setfocus(valfield);
			return false;
		}
		else {
			msg (infofield, "warn", "");   // OK
			return true;
		}
	}
	return proceed;
}

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

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

	msg (infofield, "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  (valfield,   // element to be validated
infofield,  // id of element to receive info/error msg
required)   // true if required
{
	var stat = commonCheck (valfield, infofield, required);
	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 (infofield, "error", "not a valid e-mail address");
		setfocus(valfield);
		return false;
	}

	var email2 = /^[A-Za-z][\w.-]+@\w[\w.-]+\.[\w.-]*[A-Za-z][A-Za-z]$/  ;
	if (!email2.test(tfld))
	msg (infofield, "warn", "Unusual e-mail address - check if correct");
	else
	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 validatePhone  (valfield,   // element to be validated
infofield,  // id of element to receive info/error msg
required)   // true if required
{
	var stat = commonCheck (valfield, infofield, required);
	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 (infofield, "error", "Not a valid telephone number. please enter 10 numbers");
		setfocus(valfield);
		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<10) {
		msg (infofield, "error", + numdigits + " is too short - please enter a 10 digit number");
		setfocus(valfield);
		return false;
	}

	if (numdigits>10)
	msg (infofield, "warn", numdigits + " numbers - please enter 10 numbers");
	else {
		if (numdigits<10)
		msg (infofield, "error", "Only " + numdigits + " numbers - please enter 10 numbers");
		else
		msg (infofield, "warn", "");
	}
	return true;
}