//************************************************************************************************/
// Javascript form validation routines.
//
// 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.
//************************************************************************************************/

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

//************************************************************************************************/
// function: trim
// trim leading/trailing whitespace off string
//************************************************************************************************/
function trim (str) {
	return str.replace(/^\s+|\s+$/g, '');
}//end function trim


//************************************************************************************************/
// function: setfocus
// Delayed focus setting to get around IE bug. Discovered that reason IE wasn't setting focus was
// due to an IE timing bug. Added 0.1 sec delay to fix.
//************************************************************************************************/
function setFocusDelayed () {
	global_valfield.focus();
}//end function setFocusDelayed

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


//************************************************************************************************/
// function msg
// Display warn/error message in HTML element. commonCheck routine must have previously been called
// Parameters: 
// fld = id of element to display message in
// msgtype = class to give element ("warn" or "error")
// message = string to display
//************************************************************************************************/
function msg (fld, msgtype, message) {
	// 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
}//end function msg


//************************************************************************************************/
// function 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).
// Parameters:
// valfield = element to be validated
// infofield = id of element to receive info/erro msg
// required = true if required
//************************************************************************************************/
var proceed = 2;  
function commonCheck (valfield, infofield, 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;
}//end function commonCheck


//************************************************************************************************/
// function validatePresent
// Validate if something has been entered. Returns true if so.
// Parameters:
// valfield = element to be validated
// infofield = id of element to receive info/error msg 
//************************************************************************************************/
function validatePresent (valfield, infofield ) {
	var stat = commonCheck (valfield, infofield, true);
	if (stat != proceed) {
		return stat;
	}
	
	msg (infofield, "warn", "");  
	return true;
}//end function validatePresent


//************************************************************************************************/
// function validateEmail
// Validate if e-mail address
// Returns true if so (and also if could not be executed because of old browser)
// Parameters: 
// valfield = element to be validated
// infofield = id of element to receive info/error msg
// required = true if required
//************************************************************************************************/
function validateEmail (valfield, infofield, 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;
}//end function validateEmail


//************************************************************************************************/
// function validatePhone
// Validate telephone number
// Returns true if so (and also if could not be executed because of old browser)
// Permits telephone number in format xxx-xxx-xxxx only!
// Parameters:
// valfield = element to be validated
// infofield = id of element to receive info/error msg
// required = true if required
//************************************************************************************************/
function validatePhone  (valfield, infofield, 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 = /^[1-9]\d{2}-\d{3}-\d{4}$/  ;
	if (!telnr.test(tfld)) {
		msg (infofield, "error", "* invalid number, use format xxx-xxx-xxxx");
		setfocus(valfield);
		return false;
	}
	
	//I really don't need the code below until return true...
	//but for some reason this javascript won't work without it???
	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 (infofield, "error", "ERROR: " + numdigits + " digits - too short");
		setfocus(valfield);
		return false;
	}
	
	if (numdigits>14) {
		msg (infofield, "warn", numdigits + " digits - check if correct");
	} else { 
		if (numdigits<10) {
			msg (infofield, "warn", "Only " + numdigits + " digits - check if correct");
		} else {
			msg (infofield, "warn", "");
		}
	}
	return true;
}//end function validatePhone