try {
    /*
        Developed by Robert Nyman, http://www.robertnyman.com
        Code/licensing: http://code.google.com/p/getelementsbyclassname/
    */
    var getElementsByClassName = function (className, tag, elm){
        if (document.getElementsByClassName) {
            getElementsByClassName = function (className, tag, elm) {
                elm = elm || document;
                var elements = elm.getElementsByClassName(className),
                    nodeName = (tag)? new RegExp("\\b" + tag + "\\b", "i") : null,
                    returnElements = [],
                    current;
                for(var i=0, il=elements.length; i<il; i+=1){
                    current = elements[i];
                    if(!nodeName || nodeName.test(current.nodeName)) {
                        returnElements.push(current);
                    }
                }
                return returnElements;
            };
        }
        else if (document.evaluate) {
            getElementsByClassName = function (className, tag, elm) {
                tag = tag || "*";
                elm = elm || document;
                var classes = className.split(" "),
                    classesToCheck = "",
                    xhtmlNamespace = "http://www.w3.org/1999/xhtml",
                    namespaceResolver = (document.documentElement.namespaceURI === xhtmlNamespace)? xhtmlNamespace : null,
                    returnElements = [],
                    elements,
                    node;
                for(var j=0, jl=classes.length; j<jl; j+=1){
                    classesToCheck += "[contains(concat(' ', @class, ' '), ' " + classes[j] + " ')]";
                }
                try {
                    elements = document.evaluate(".//" + tag + classesToCheck, elm, namespaceResolver, 0, null);
                }
                catch (e) {
                    elements = document.evaluate(".//" + tag + classesToCheck, elm, null, 0, null);
                }
                while ((node = elements.iterateNext())) {
                    returnElements.push(node);
                }
                return returnElements;
            };
        }
        else {
            getElementsByClassName = function (className, tag, elm) {
                tag = tag || "*";
                elm = elm || document;
                var classes = className.split(" "),
                    classesToCheck = [],
                    elements = (tag === "*" && elm.all)? elm.all : elm.getElementsByTagName(tag),
                    current,
                    returnElements = [],
                    match;
                for(var k=0, kl=classes.length; k<kl; k+=1){
                    classesToCheck.push(new RegExp("(^|\\s)" + classes[k] + "(\\s|$)"));
                }
                for(var l=0, ll=elements.length; l<ll; l+=1){
                    current = elements[l];
                    match = false;
                    for(var m=0, ml=classesToCheck.length; m<ml; m+=1){
                        match = classesToCheck[m].test(current.className);
                        if (!match) {
                            break;
                        }
                    }
                    if (match) {
                        returnElements.push(current);
                    }
                }
                return returnElements;
            };
        }
        return getElementsByClassName(className, tag, elm);
    };


    /**** other helpers *****/

    //patch for Opera

    if (!Node.prototype) {
        var node=document.createTextNode('');
        var Node = node.constructor;
    }
    // removeNode itself
    if (window.Node) Node.prototype.removeNode = function(removeChildren) {
        var self = this;
        if (Boolean(removeChildren))
            return this.parentNode.removeChild( self );
        else {
            var r=document.createRange();
            r.selectNodeContents(self);
            return this.parentNode.replaceChild(r.extractContents(),self);
        }
    }
} catch(e) {
  // whatever
  //alert(e);
}
function insertAfter(newChild, refChild) {
    refChild.parentNode.insertBefore(newChild,refChild.nextSibling);
}
function removeAllChilds(obj){
    while(obj.hasChildNodes() == true) {
        obj.removeChild(obj.firstChild);
    }
}