I am building a photo slider in JavaScript and jQuery. It works perfectly in chrome, but not in IE6 where I know most of my clients would view it.
I have this function:
function getFacebookPhotos(photoCount, pageId) {
    var picsUrl = "http://api.facebook.com/method/fql.query?query=SELECT%20src_big,%20src_big_height,%20src_big_width%20FROM%20photo%20WHERE%20pid%20IN%20(SELECT%20pid%20FROM%20photo_tag%20WHERE%20subject='243117879034102')%20OR%20pid%20IN%20(SELECT%20pid%20FROM%20photo%20WHERE%20aid%20IN%20(SELECT%20aid%20FROM%20album%20WHERE%20owner='" + pageId + "'%20AND%20type!='profile'))";
    var responseText = $.ajax({
        url: picsUrl,
        async: false,
        dataType: "xml",
        success: function(text) {
            responseText = text;
        }
    }).responseText;
    var xmlDoc = $.parseXML(responseText);
    var $xml = $(xmlDoc);
    var $photos = $xml.find("photo");
    var resultantPhotos = [];
    for (var i = 0; i < photoCount; i++) 
    {
        var $element = $($photos[i]);
        var $src_big = $element.find("src_big");
        var $text = $src_big.text();
        resultantPhotos.push($text);
    }
    return resultantPhotos;
}
It fetches the XML response from a facebook query, parses it, and returns an array of photo urls from a facebook page. In Chrome, this works, but in Internet Explorer 6, the returned photo array is null. In both browsers the code executes without error.
I was using this JavaScript to parse the XML:
if (window.XMLHttpRequest) { 
    xmlHttp = new XMLHttpRequest();
}
else {
    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlHttp.open("GET", picsUrl, false); // Throws permission error in IE
xmlHttp.send(null);
var photos;
if (window.DOMParser) 
{
    var parser = new DOMParser();
    xml = parser.parseFromString(responseText, "text/xml");
} 
else  // Internet Explorer
{
    xml = new ActiveXObject("Microsoft.XMLDOM");
    xml.async = false;
    xml.loadXML(responseText);
}
photos = xml.getElementsByTagName("photo");
But that gave me errors in IE while still working in Chrome so I switched to jQuery. Do you know what's wrong with it?
