function isNumeric(elem, helperMsg){
	var numericExpression = /^[0-9]+$/;
	if(document.getElementById(elem).value.match(numericExpression)){
		return true;
	}else{
		alert(helperMsg);
		document.getElementById(elem).focus();
		return false;
	}
}

function notEmpty(elem, helperMsg){
	if(document.getElementById(elem).value.length == 0){
		alert(helperMsg);
		document.getElementById(elem).focus(); 
		return false;
	}
	return true;
}

function notEmptyCombo(elem, helperMsg){
	if(document.getElementById(elem).value == 0){
		alert(helperMsg);
		document.getElementById(elem).focus(); 
		return false;
	}
	return true;
}

function isAlphabet(elem, helperMsg){
	var alphaExp = /^[a-zA-Z]+$/;
	if(document.getElementById(elem).value.match(alphaExp)){
		return true;
	}else{
		alert(helperMsg);
		document.getElementById(elem).focus();
		return false;
	}
}

function isAlphanumeric(elem, helperMsg){
	var alphaExp = /^[0-9a-zA-Z]+$/;
	if(document.getElementById(elem).value.match(alphaExp)){
		return true;
	}else{
		alert(helperMsg);
		document.getElementById(elem).focus();
		return false;
	}
}

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