// JavaScript Document
function loginSystem(){
 var obj = document.getElementById('loginform');
 var item1 =  document.getElementById('username').value;
 var item2 =  document.getElementById('password').value;

 ( item1 != null && item1 != '' && item2 != null && item2 != "") ? clear() : alert("Error: user name and password can not be NULL!!");
}
function clear(obj){
	var obj = document.getElementById('loginform');
	obj.submit(); 
	document.getElementById('username').value = '';
	document.getElementById('password').value = '';
	}