function check_login(form){
	var username = form.username.value;
	var password = form.password.value;
if(username!="" && password!=""){
	$("#login_button").hide();
	$("#overlayLoading").fadeIn(500);
	var url="check_login.php"; 
	var dataSet={ username:username,password:password };
	$.post(url,dataSet,function(data){
								//alert (data);
		if(data==0){
			$("#overlayLoading").hide();
			$("#login_button").show();
			$("#username_wrong").html(" Wrong username or password!!");
		}else if(data==1){
			
			//alert("success");
			$("#username_wrong").hide();
			window.location = 'http://www.achallenges.com/strategic/index.php'; 
		}
	});
}else{
	alert("กรุณากรอก Username และ Password!");
}
}