IIS7.5已启用父路径，new Ajax.Request('../../路径,options);404错误无法找到资源

iis7.5， 无法自动根据相对路径找到对应网页

function selectFile(type,obj,height,width)
{

var vitualPath=getRootPath();
var ShowObj = obj;
if(isArray(obj) && obj.length > 1)
ShowObj = obj[1];
showfDiv(ShowObj,"loading...",width);
LastSelectObj = obj;

var options={
method:'get',
parameters:"heights="+ height,
onComplete:function(transport)
{
var returnvalue=transport.responseText;
if (returnvalue.indexOf("??")>-1)
showfDiv(ShowObj,'Error',width);
else
var tempstr=returnvalue;
showfDiv(ShowObj,tempstr,width);
}
};
var arrtype=type.split("|")[0]
switch(arrtype)
{
case "file":
new Ajax.Request('../../configuration/system/iframe.aspx?FileType=file',options);
break;
case "pic":
new Ajax.Request('../../configuration/system/iframe.aspx?FileType=pic',options);
break;
[解决办法]