// ----------------------------------------------------------------------
// 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) {
	global_valfield = valfield;
	setTimeout( 'setFocusDelayed()', 100 );
}


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

function msg(fld, msgtype, message) {
	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;
}

// --------------------------------------------
//            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, infofield, required) {
	if (!document.getElementById) {
		return true;
	}
	
	var elem = document.getElementById(infofield);
	if (!elem.firstChild) {
		return true;
	}
	
	if (elem.firstChild.nodeType != node_text) {
		return true;
	}
	
	if (emptyString.test(valfield.value)) {
		if (required) {
			msg (infofield, "error", "ERROR: dit veld is verplicht");
			setfocus(valfield);
			return false;
		} else {
			msg (infofield, "warn", "");
		}
	}
	return proceed;
}

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

function validatePresent(valfield, infofield) {
	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, infofield, required) {
	var tfld = trim(valfield.value);
	var email = /^[^@]+@[^@.]+\.[^@]*\w\w$/  ;
	if (!email.test(tfld)) {
		msg (infofield, "error", "ERROR: geen geldig emailadres");
		setfocus(valfield);
		return false;
	}
	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, infofield, required) {
	var tfld = trim(valfield.value);
	var telnr = /^\+?[0-9 ()-]+[0-9]$/  ;
	if (!telnr.test(tfld)) {
		msg (infofield, "error", "ERROR: Geen geldig telefoonnummer ingevoerd");
		setfocus(valfield);
		return false;
	}
	return true;
}

// --------------------------------------------
//             validateNum
// Only digits
// Returns true if OK 
// --------------------------------------------

function validateNum (valfield, infofield, required) {
	var tfld = trim(valfield.value);
	var numRE = /^[0-9]/
	if (!numRE.test(tfld)) {
		msg (infofield, "error", "ERROR: geen geldig nummer ingevuld");
		setfocus(valfield);
		return false;
	}
	return true;
}