Reading XML, problem accesing and counting elements

Reading XML, problem accesing and counting elements

I'm trying to access an XML file, but it doesn't seem to work, this is an example of the XML:
<?xml version="1.0" encoding="ISO-8859-1"?>
<pics>
   <pic>
      <autor>rtteewt</autor>
      <desc>trhtrhtreherhetrhhrh</desc>
   </pic>
   <pic>
      <autor>tewtewt</autor>
      <desc>hytjyujryukukyyu.</desc>
   </pic>
   <pic>
      <autor>5yutru</autor>
      <desc>fghgyhvehtyudyd</desc>
   </pic>
   <pic>
      <autor>jhgjgfj</autor>
      <desc>trhythtrjtikui</desc>
   </pic>
</pics>

This is a simple jquery function I'm using just to check if Im able to read the content:
var total = 0;
function readXML(section)
   var xml = $.ajax(
   {
      type: "GET",
      url : "xmldocs/picslist.xml",
      dataType: "xml",
      success: function(xml)
      {

            total = xml.getElementsByTagName("pic").length;

      }
   });
   alert(total);
}   

I'm getting 0 all the time...