URL not being sent in AJAX

[rajug]

Hello there,

I have a problem using a simple AJAX.
I have following HTML:

<div id="divComments" style="border:1px #000000 inset;width:400px;height:150px;overflow:auto;background-color:#FFFFFF;padding:2px;"></div>
		  <input name="cCommentID" type="text" value="" id="cCommentID">
		  <input name="totalComments" type="text" id="totalComments" value="<?php echo $TotalCommentsPHP;?>">
<table width="400" border="0" cellspacing="0" cellpadding="0">
            <tr>
              <td width="32&#37;" align="left"><a href="javascript:void(null);" onClick="PreviousComment();">&laquo; Previous</a></td>
              <td width="68%" align="right"><a href="javascript:void(null);" onClick="NextComment();">Next &raquo;</a></td>
            </tr>
          </table>

And I have this javascript code:

var jsComID=new Array();
jsComID[0]=1;
jsComID[1]=2;
jsComID[2]=3;
var objXMLHttp = null;
if(window.XMLHttpRequest)
	objXMLHttp = new XMLHttpRequest();
else if(window.ActiveXObject)
	objXMLHttp = new ActiveXObject("Microsoft.XMLHTTP");
if (objXMLHttp == null){
	alert ("Browser does not support HTTP Request");
}
function getObj(name){
	if (document.getElementById){
		this.obj = document.getElementById(name);
	}
	else if (document.all){
		this.obj = document.all[name];
	}
	else if (document.layers){
		this.obj = document.layers[name];
	}
	return this.obj
}
function ShowComment(url){
	objXMLHttp.onreadystatechange=AfterOperation;
	objXMLHttp.open("GET", url, true);
	objXMLHttp.send(null);
}
function AfterOperation(){
	var divObj = getObj('divComments');
	if(objXMLHttp.readyState == 1){
		//divObj.disabled = true;
	}
	if(objXMLHttp.readyState == 4 || objXMLHttp.readyState == "complete"){
		//divObj.disabled = false;
		divObj.innerHTML = objXMLHttp.responseText
	}
}
var commentidObj1 = getObj('cCommentID');
commentidObj1.value = 0;
ShowComment('./modules/projects/show_comments.php?project_id=<?php echo $_GET['project_id'];?>&comment_id=' + jsComID[commentidObj1.value]);

function PreviousComment(){
	var comid = "";
	var totalObj = getObj('totalComments');
	var commentidObj = getObj('cCommentID');
	if(commentidObj.value == 0){
		comid = totalObj.value;
	}
	else{
		comid = parseInt(commentidObj.value) - 1;
	}
	ShowComment('./modules/projects/show_comments.php?project_id=<?php echo $_GET['project_id'];?>&comment_id=' + jsComID[comid]);
	commentidObj.value = comid;
}
function NextComment(){
	var comid = 0;
	var totalObj = getObj('totalComments');
	var commentidObj = getObj('cCommentID');
	if(commentidObj.value == totalObj.value){
		comid = 0;
	}
	else{
		comid = parseInt(commentidObj.value) + 1;
	}
	ShowComment('./modules/projects/show_comments.php?project_id=<?php echo $_GET['project_id'];?>&comment_id=' + jsComID[comid]);
	commentidObj.value = comid;
}
//====================================

What i want is, just pass the Previous and Next comment to retrive comment in the div. It works fine in FF but nothing even error in IE 6. The URL that i passed on the onClick is not being sent to the server.
What may be the problem there?

Thank you in advance.