[jQuery] AJAX Problem

[jQuery] AJAX Problem


hi guys,
i am trying to write a simple ajax code with $.ajax() function.
however the Firebug plug-in in Firefox show this error:
[Exception... "'Permission denied to call method XMLHttpRequest.open'
when calling method: [nsIDOMEventListener::handleEvent]" nsresult:
"0x8057001e (NS_ERROR_XPC_JS_THREW_STRING)" location: "<unknown>"
data: no]
in the IE it is working there is not any problem.
my code is this:
var txt = $.ajax({
            url:"http://../../Posts.xml",
            type:"GET",
            dataType:"xml"
        }).responseText;
i need help. thnks...