function isDigit(obj,errMessage)   
{   
	var patrn=/^[0-9]{1,13}$/;   

	if (!patrn.exec(obj.value)) {
		 alert(errMessage);  
		 obj.focus();
		 return false;
	}
	return true  
} 

function isURL(obj,errMessage) {
	var partn = /^(ftp|http|https):\/\//;
	
	if (!partn.exec(obj.value)) {
		alert(errMessage);
		obj.focus();
		return false;
	}
	
	return true;
	
}


function isEmpty(obj,errMessage) {
	var partn = /^\s*$/;
	
	if (partn.exec(obj.value)) {
		alert(errMessage);
		return false;
	}
	
	return true;
}


function checkLen(obj,len,errMessage) {
	if (obj.value.length > len) {
		alert(errMessage);
		obj.focus();
		return false;
	}
	
	return true;
}

function checkCatedirectory(obj,message) {
	var partn = /^\w{3,50}$/;

	if (!partn.exec(obj.value)) {
		alert(message);
		obj.focus();
		return false;
	}

	return true;
}

function checkEmail(obj,message) {
	var partn = /^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$/

	if (!partn.exec(obj.value)) {
		alert(message);
		obj.focus();
		return false;
	}

	return true;
}

function checkPassword(password,confimpassword,passwordlen,message1,message2) {
	if (password.value != confimpassword.value) {
		alert(message1);
		password.focus();
		return false;
	}
	
	if (password.value.length > passwordlen) {
		alert(message2);
		password.focus();
		return false;
	}
	
	return true;
}

// check if it is a tel number
function isTelNumber(){
	//http://topic.csdn.net/t/20041126/17/3592210.html
	var partn = /^(13\d{9}(;13\d{9})*)|(\(\d{3,4}\)|\d{3,4}-)?\d{7,8}(;(\(\d{3,4}\)|\d{3,4}-)?\d{7,8})*$/	
}