"uncaught exception: permission denied to call method XMLHttpRequest.open"

I'm running JSP file on Apache Tomcat.  It embeds Javascript codes that send XMLHttpRequest to a website (http://api.clickatell.com/http/sendmsg) and (is supposed to) receive response.

This doesn't work on IE and Firefox, however, due to some security restrictions.  The javascript error message is:

            "uncaught exception: permission denied to call method XMLHttpRequest.open"

I researched the web and found that the solution is by enabling UniversalBrowserRead setting.  So, I copied and added these lines:

            try {
                        netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead");
            } catch (e) {
                        alert("Permission UniversalBrowserRead denied.");
            }

This works on a standalone HTML file, but when I deployed it into Apache-Tomcat server, it doesn't work anymore.  It doesn't allow the UniversalBrowserRead to be enabled.

So, what should I do now?  What is the cause of this?  Should I add some browser security configuration using .htaccess?  

Below is the complete line of the Javascript codes:

<script language="javascript" type="text/javascript">
<!--
                        function sendSMS(url, data) {
                  
                  alert("test");
                  var res;
                  var req;
                  
                  try {
                        req = new XMLHttpRequest();
                  }
                  catch(error) {
                        try{
                              req=new  ActiveXObject("Microsoft.XMLHTTP");
                        }
                        catch(error) {
                              req=null;
                        }
                  }
            try {
                        netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead");
                  } catch (e) {
                        alert("Permission UniversalBrowserRead denied.");
                  }
                    req.open("POST", url, false);
                  req.setRequestHeader ("Content-Type", "application/x-www-form-urlencoded");
                  req.send(data);
                  res= req.readyState;
                  
                  alert("test");
                  return res;
            }
                        
                        sendSMS("<%out.print(sUrl);%>", "<%out.print(sPostData);%>");
//-->
</script>

Thanks!!