function $(id)
{
  return document.getElementById(id);
}

function GetHttpObject() 
{
    if (typeof XMLHttpRequest != 'undefined')
        return new XMLHttpRequest();
    try 
    {
        return new ActiveXObject("Msxml2.XMLHTTP");
    } 
    catch (e) 
    {
        try 
        {
            return new ActiveXObject("Microsoft.XMLHTTP");
        } 
        catch (e) {}
    }    
    return false;
}
function getImages(imgType)
{
	var http = GetHttpObject();
    $("imageList").innerHTML = "<span style='border:1px solid #002B5E;display:block;'><img src='images/loading.gif'/>正在获取图片列表，请稍候……</span>";
	var url; 
	if(imgType != "")
	{
			url="getImages.asp?imgType=" + escape(imgType);			 
	}
	else
		url="getImages.asp";
	
    http.onreadystatechange=function()
	{
		if(http.readyState == 4)
		{
			if(http.responseText.length > 0)
			{
				$("imageList").innerHTML=unescape(http.responseText);
			}
			else
			{
				$("imageList").innerHTML="<span style='border:1px solid #AFDA8C;display:block;padding:5px;margin-right:0.5em'>对不起，读取图片列表失败</span>";
			}
		}		
	}
	http.open("get", url, true);
	http.send(null);	
}