var http_request = false;
   function makeRequest(url, parameters) {
      http_request = false;
      if (window.XMLHttpRequest) { // Mozilla, Safari,...
         http_request = new XMLHttpRequest();
         if (http_request.overrideMimeType) {
            http_request.overrideMimeType('text/html');
         }
      } else if (window.ActiveXObject) { // IE
         try {
            http_request = new ActiveXObject("Msxml2.XMLHTTP");
         } catch (e) {
            try {
               http_request = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
         }
      }
      if (!http_request) {
         alert('Cannot create XMLHTTP instance');
         return false;
      }
      http_request.onreadystatechange = alertContents;
      http_request.open('GET', url + parameters, true);
      http_request.send(null);
   }

   function makePostRequest(url, parameters,dump,span,chatmode) {
      http_request = false;
      if (window.XMLHttpRequest) { // Mozilla, Safari,...
         http_request = new XMLHttpRequest();
         if (http_request.overrideMimeType) {
            http_request.overrideMimeType('text/html');
         }
      } else if (window.ActiveXObject) { // IE
         try {
            http_request = new ActiveXObject("Msxml2.XMLHTTP");
         } catch (e) {
            try {
               http_request = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
         }
      }
      if (!http_request) {
         alert('Cannot create XMLHTTP instance');
         return false;
      }
      http_request.open('POST',url,true);
      http_request.onreadystatechange = function(){
	if (http_request.readyState == 4){
    	    if (http_request.status == 200){
        	result = http_request.responseText;
		if(result.match("<done>")) document.location="login.php";
		if(result.match("<index>")) document.location="index.php";
		if(result.match("hacking attempt!")) document.location="http://www.teletubbies.com";
		r=result.match("<key ([^>]+)>");
		if(r) document.frm.check.value=r[1];
		if(!span) span="myspan";
		if(dump){
		    if(document.getElementById(span)) {
			var text=document.getElementById(span).innerHTML;
			if(result.length>0) {	//evitamos parpadeos con setTimeout
			    document.getElementById(span).innerHTML=(span=="chatbody")?rot13(result):result;
			    if(span=="chatbody") {
				document.getElementById("chatmsg").scrollTop=9999999;
			    }
			} 
		    }
		}else 
		    eval(result);
		}
	}
      }
//      http_request.setRequestHeader("Connection", "Close");
      http_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
      http_request.setRequestHeader("Ajax-Accept", "true");
      http_request.setRequestHeader("Content-length", parameters.length);
      http_request.send(parameters);
   }

   function alertContents() {
      if (http_request.readyState == 4) {
      if (http_request.status == 200)
          {
            //alert(http_request.responseText);
            result = http_request.responseText;
	    if(result=="<done>") document.location="login.php";
	    if(result=="<index>") document.location="index.php";
    	    document.getElementById('myspan').innerHTML = result;
         } else {
            alert('There was a problem with the request.');
         }
      }
   }