// If the length of the element's string is 0 then display helper message
function isEmpty(elem, helperMsg){
	if(elem.value.length == 0){
		alert(helperMsg);
		elem.focus(); // set the focus to this input
		return true;
	}
	return false;
}


// If the element's string matches the regular expression it is all numbers and, optionally, whitespace
function isNumeric(elem, helperMsg, allowWhiteSpace){
	if (allowWhiteSpace) {
		var numericExpression = /^[0-9\s]+$/;
	} else {
		var numericExpression = /^[0-9]+$/;
	}
	if(elem.value.match(numericExpression)){
		return true;
	}else{
		alert(helperMsg);
		elem.focus();
		return false;
	}
}


// If the element's string matches the regular expression it is all letters and, optionally, whitespace
function isAlphabet(elem, helperMsg, allowWhiteSpace){
	if (allowWhiteSpace) {
		var alphaExp = /^[a-zA-Z\s]+$/;
	} else {
		var alphaExp = /^[a-zA-Z]+$/;
	}
	if(elem.value.match(alphaExp)){
		return true;
	}else{
		alert(helperMsg);
		elem.focus();
		return false;
	}
}


// If the element's string matches the regular expression it is numbers and letters and, optionally, whitespace
function isAlphanumeric(elem, helperMsg, allowWhiteSpace){
	if (allowWhiteSpace) {
		var alphaExp = /^[0-9a-zA-Z\s]+$/;
	} else {
		var alphaExp = /^[0-9a-zA-Z]+$/;
	}
	if(elem.value.match(alphaExp)){
		return true;
	}else{
		alert(helperMsg);
		elem.focus();
		return false;
	}
}


function lengthRestriction(elem, min, max){
	var uInput = elem.value;
	if(uInput.length >= min && uInput.length <= max){
		return true;
	}else{
		alert("Please enter between " +min+ " and " +max+ " characters");
		elem.select();
		return false;
	}
}


function emailValidator(elem, helperMsg){
	var emailExp = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;
	if(elem.value.match(emailExp)){
		return true;
	}else{
		alert(helperMsg);
		elem.focus();
		return false;
	}
}


function checkPassWords(elem1, elem2, helperMsg) {
	if (elem1.value == elem2.value) {
		return true;
	} else {
		alert(helperMsg);
		elem1.value="";
		elem2.value="";
		elem1.focus();
		return false;
	}
}

function checkPasswordText(elem, helperMsg) {
	if ((elem.value.indexOf(";") == -1) && (elem.value.indexOf("'") == -1) && (elem.value.indexOf("1=1") == -1) && (elem.value.indexOf('"') == -1) && (elem.value.indexOf("\\") == -1) && (elem.value.indexOf("/") == -1)) {
		return true;
	} else {
		alert(helperMsg);
		elem.value="";
		elem.focus();
		return false;
	}
}

function checkAge(elem, helperMsg) {
	if (elem.checked==true) {
		return true;
	} else {
		alert(helperMsg);
		elem.focus();
		return false;
	}
}

function checkNotZero(elem, helperMsg) {
	if (elem.value>0) {
		return true;
	} else {
		alert(helperMsg);
		elem.focus();
		return false;
	}
}