Simple AJAX request using jQuery not working on IE

This is my code, which sometimes works and sometimes doesn't.

var resolve_ajax_login=function(){
  $.ajaxSetup({cache:false });
  var loginvar=$("#inputlogin").attr("value");
  var senhavar=$("#inputsenha").attr("value");
  $.post("../model/php/login_ajax.php",
        {login:loginvar, senha:senhavar},
        function(responseText){
            if (responseText=="ok"){ 
                window.location="areatrab.php";

            }else{
                $("#inputlogin").attr("value","");
                $("#inputsenha").attr("value","");
                $("#divmensagem").html("<span style='color:red;font-size:70%;'>"+responseText+"</span>");

            }
        }
  );
  return false;
}开发者_开发问答;

Ok. It's in portuguese but I think you get the general picture. Sometimes this works, no problem, but some other times (only in IE, no problem whatsoever in Firefox) it throws a javascript error in my jquery.js file (minified). The error description is as follows:

Object doesn't support this property or method: jquerymin.js line 123 character 183..

which amounts to...

{return new A.XMLHttpRequest}

somewhere in the middle of the jquery.js file. It seems to be very IE-specific, as I had no such problems on Firefox. This guy apparently had the same problem as I did, but got no responses yet.

Has anyone else seen this? Thanks in Advance

P.S.: I run IE 8

Have you tried using a full URL instead of ../model...? For example: http://www.mysite.com/model/login_ajax.php

Also, maybe try modifying the 'xhr' property using jQuery's .ajax method... something like:

var loginvar = $("#inputlogin").val();
var senhavar = $("#inputsenha").val();
var ajax_obj = null;

var resolve_ajax_login = function() {
  if(ajax_obj !== null) {
    try {
      ajax_obj.abort();
    } catch(e) {
    }
  }

  ajax_obj = $.ajax({
    type: 'POST',
    cache: false,
    url: '../model/php/login_ajax.php',
    data: {login:loginvar, senha:senhavar},
    dataType: 'text',
    timeout: 7000,
    success: function(data)
    {
      if(response == 'ok') {
        alert("right on!");
      } else {
        alert("not ok");
        return;
      }
    },
    error: function(req, reqStatus, reqError)
    {
      alert("error");
      return;
    },
    'xhr': function() {
      if(ajax_obj !== null) {
        return ajax_obj;
      }

      if($.browser.msie && $.browser.version.substr(0,1) <= 7) {
        return new ActiveXObject("Microsoft.XMLHTTP");
      } else {
        return new XMLHttpRequest();
      }
    }
  });
}

It's something to do with the order in which you try all the different types of browsers in order to create the right kind of XMLHTTP REQUEST object.. I'll explain it in more detail in the following page:

AJAX inconsistency in IE 8?