function ltrim(s) {
	return s.replace(/^\s*/, "");
} 

function rtrim(s) { 
	return s.replace(/\s*$/, ""); 
} 

function trim(s) { 
	return rtrim(ltrim(s)); 
}

function validateForm() {
	//alert("validateForm");
	var strMsg = "", returnFlag = true;
	var regExpEmail = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;

	var firstname = trim(document.bookingForm.firstname.value);
	var surname = trim(document.bookingForm.surname.value);
	var contactNumber = trim(document.bookingForm.contactNumber.value);
	var email = trim(document.bookingForm.email.value);
	var id = trim(document.bookingForm.id.value);
	var branch = document.bookingForm.branch.selectedIndex;
	var date1 = trim(document.bookingForm.date1.value);
	var date2 = trim(document.bookingForm.date2.value);
	

	if (firstname=="") {
		strMsg = strMsg + "- Your Firstname cannot be empty.\n";
		returnFlag = false;
	}
	if (surname=="") {
		strMsg = strMsg + "- Your Surname cannot be empty.\n";
		returnFlag = false;
	}
	if ((contactNumber=="") || (contactNumber=="mobile or tel")) {
		strMsg = strMsg + "- Your Contact Number cannot be empty.\n";
		returnFlag = false;
	}

	if (email=="") {
		//strMsg = strMsg + "- Your Email Address cannot be empty.\n";
		//returnFlag = false;
	} else if (regExpEmail.test(email)==false) {
		strMsg = strMsg + "- Your Email Address is invalid.\n";
		returnFlag = false;
	}

	/*if (id=="") {
		strMsg = strMsg + "- Your ID cannot be empty.\n";
		returnFlag = false;
	}*/

	if (branch==0) {
		strMsg = strMsg + "- Branch must be selected.\n";
		returnFlag = false;
	}
		
	if ((date1=="") || (date1=="preferred date")) {
		strMsg = strMsg + "- Your Booking Date cannot be empty.\n";
		returnFlag = false;
	}

	if ((date2=="") || (date2=="preferred time")) {
		strMsg = strMsg + "- Your Booking Time cannot be empty.\n";
		returnFlag = false;
	}
		
	//display error(s)
	if (returnFlag) {
		document.bookingForm.submit();
	}
	else {
		alert("Please correct the following error(s) in your submission:\n\n" + strMsg);
	}
	
	//return returnFlag;	//able OR disable the submit button
}

//alert("loaded");