function InitAjax()
{
    var ajax=false;
    try        /*IE*/
    {
    ajax=new ActiveXObject("Msxml1.2XMLHTTP");
    }
    catch(e)
    {
    try        /*IE*/
        {
            ajax=new ActiveXObject("Microsoft.XMLHTTP");
        }
    catch (E)
        {
            ajax=false;
        }
    }
    if(!ajax && typeof XMLHttpRequest!='undefined')    /*非IE*/
    {
    ajax=new XMLHttpRequest();
    }
    return ajax;
}

var kwkAjax = {};
/*
	data {name:'xxx',age:10}
*/
kwkAjax.get = function(url,data,loaded,loading){
	
		var ajax = InitAjax();
		ajax.open("GET", url, true);
		
		var p_arguments = arguments;
		
		ajax.onreadystatechange = function()
		{
			if(ajax.readyState == 4)
			{
				if(p_arguments.length>=3)
					loaded.apply(null,[ajax]); 

			}else{
				if(p_arguments.length>=4)
					loading.call(null);
			}
		}
		ajax.setRequestHeader("If-Modified-Since","0");  
		ajax.send(kwkAjax.parseParam(data));
}

kwkAjax.parseParam=function(data)
{
	var arr =[]
		for(var key in data)
		{
			arr.push(key+"="+data[key])
		}
	return arr.join("&");	
}