Question

$(document).ready(function() {
  function ajaxselectrss(rssurlvar) {
  var ajaxRequest;  // The variable that makes Ajax possible!

 try{
  // Opera 8.0+, Firefox, Safari
  ajaxRequest = new XMLHttpRequest();
 } catch (e){
  // Internet Explorer Browsers
  try{
   ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
  } catch (e) {
   try{
    ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
   } catch (e){
    // Something went wrong
    alert("Your browser broke!");
    return false;
   }
  }
 }
 // Create a function that will receive data sent from the server
 ajaxRequest.onreadystatechange = function(){
  if(ajaxRequest.readyState == 4){

   var ajaxDisplay = document.getElementById('news');
   ajaxDisplay.innerHTML = ajaxRequest.responseText;
  }
 }



 //var rssurlvar = $(this).attr("title");
 var queryString = "rurl=" + rssurlvar;
 var urltofile = "rssget.php";
 ajaxRequest.open("POST", urltofile, true);
 ajaxRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
 ajaxRequest.setRequestHeader("Content-length", queryString.length);
 ajaxRequest.setRequestHeader("Connection", "close");
 ajaxRequest.send(queryString); 

}
    $(".rshownews").click(function() {
        window.setInterval(function() {ajaxselectrss($(this).attr("title"))}, 1000);
    });
});

The POST query is “undefined” (Firebug).

Answer 1

You should use $.ajax – it will standardise the whole XmlHTTPRequest thing across browsers.

$.ajax({
    type: "POST",
    url: "rssget.php",
    data: queryString,
    success: function(data) {
      $('#news').html(data);
    }
});

(And, BTW, if you setInterval in your click handler, you will start a new periodic call to your ajaxselectrss function every time the button is clicked.)

Also, your context has changed due to the wrapper function. Try changing your click handler like so:

$(".rshownews").click(function() {
  var _this = this;
  window.setInterval(function() {ajaxselectrss($(_this).attr("title"))}, 1000);
});