function checkInvoiceNumber(){
	var invoice = document.getElementById('invoice');
	var zipcode = document.getElementById('zipcode');
	var lastname = document.getElementById('lastname');
	
	   if(isEmpty(invoice, "Invoice Number is required!")){
			return false;
		}else if(isNumeric(invoice, "Please Input a valid invoice number!")==false){
			return false;
		}else if(isEmpty(zipcode, "Zipcode is required!")){
			return false;
		}else if(isEmpty(lastname, "Consignee's Lastname is required!")){
			return false;
		}else{
			return true;
		}
		
}
function validatefileupload(){
	var invoice = document.getElementById('invoiceno');
	var imgfile = document.getElementById('imgfile');
	
	   if(isEmpty(invoice, "Invoice Number is required!")){
			return false;
		}else if(isNumeric(invoice, "Please Input a valid invoice number!")==false){
			return false;
		}else if(isEmpty(imgfile, "File is required!")){
			return false;
		}else{
			return true;
		}
		
}
function isEmpty(elem, helperMsg){
	if(elem.value.length == 0){
		alert(helperMsg);
		elem.focus(); // set the focus to this input
		return true;
	}
		return false;
}
function chckAgreement(elem, helperMsg){
	if(elem.checked==false){
		alert(helperMsg);
		elem.focus(); // set the focus to this input
		return true;
	}
		return false;
}
function isNumeric(elem, helperMsg){
	var numericExpression = /^[0-9]+$/;
	if(elem.value.match(numericExpression)){
		return true;
	}else{
		alert(helperMsg);
		elem.focus();
		return false;
	}
}

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

function isAlphanumeric(elem, helperMsg){
	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.focus();
		return false;
	}
}

function madeSelection(elem, helperMsg){
	if(elem.value == "Please Choose"){
		alert(helperMsg);
		elem.focus();
		return false;
	}else{
		return true;
	}
}

function emailValidator(elem, helperMsg){
	var emailExp = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;
	 if(elem.value.match(emailExp)){
		return false;
	}else{
		alert(helperMsg);
		elem.focus();
		return true;
	}
	
	if(elem.value.length == 0){
		alert(helperMsg);
		elem.focus(); // set the focus to this input
		return true;
	}
		return false;
}