/** XHConn - Simple XMLHTTP Interface - bfults@gmail.com - 2005-04-08        **
 ** Code licensed under Creative Commons Attribution-ShareAlike License      **
 ** http://creativecommons.org/licenses/by-sa/2.0/                           **/
function XHConn()
{
  var xmlhttp, bComplete = false;
  try { xmlhttp = new ActiveXObject("Msxml2.XMLHTTP"); }
  catch (e) { try { xmlhttp = new ActiveXObject("Microsoft.XMLHTTP"); }
  catch (e) { try { xmlhttp = new XMLHttpRequest(); }
  catch (e) { xmlhttp = false; }}}
  if (!xmlhttp) return null;
  
  var getQSFromMap = function (map) {
		var buffer = new Array();
		for (var i in map) {
			buffer[buffer.length] = i+"="+map[i];
		}
		return buffer.join("&");
  }
	
  this.connect = function(sURL, sMethod, sParams, fnDone, fnError)
  {
    if (!xmlhttp) return false;
    bComplete = false;
    sMethod = sMethod.toUpperCase();

    var sVars;
	if (typeof sParams == 'object') {
		sVars= getQSFromMap(sParams)
	}
	else {
		sVars = sParams;
	}
    try {
      if (sMethod == "GET")
      {
        xmlhttp.open(sMethod, sURL+"?"+sVars, true);
        sVars = "";
      }
      else
      {
        xmlhttp.open(sMethod, sURL, true);
        xmlhttp.setRequestHeader("Method", "POST "+sURL+" HTTP/1.1");
        xmlhttp.setRequestHeader("Content-Type",
          "application/x-www-form-urlencoded");
      }
      xmlhttp.onreadystatechange = function(){
        if (xmlhttp.readyState == 4 && !bComplete)
        {
		  if ((xmlhttp.status == 200) && (xmlhttp.statusText == "OK")) {
	          bComplete = true;
	          fnDone(xmlhttp.responseText);
		  }
          else {
          bComplete = true;
          fnError(xmlhttp);        	
	      }
        }
        };
      xmlhttp.send(sVars);
    }
    catch(z) { return false; }
    return true;
  };
  return this;
}