var request;

//event handler for XMLHttpRequest
function handleJson_new(resp){
    var func = new Function("return "+resp);
    var objt = func();
    var servicename = objt.service;
    span = document.getElementById(servicename);
    span.innerHTML = objt.answer;
}

//event handler for XMLHttpRequest
function handleJson(resp){
    var func = new Function("return "+resp);
    var objt = func();

    if (!objt.service) {
      var currentprice = objt.currentprice;
      element = document.getElementById('currentprice');
      element.setAttribute('value', currentprice);
    } else {
      var servicename = objt.service;
      span = document.getElementById(servicename);
      span.innerHTML = objt.answer;
    }
}

/* Wrapper function for constructing a Request object.
 Parameters:
  reqType: The HTTP request type such as GET or POST.
  url: The URL of the server program.
  asynch: Whether to send the request asynchronously or not.
*/
function httpRequest(reqType,url,asynch){

    //Mozilla-based browsers
    if(window.XMLHttpRequest){
        request = new XMLHttpRequest();
    } else if (window.ActiveXObject){
        request=new ActiveXObject("Msxml2.XMLHTTP");
        if (! request){
            request=new ActiveXObject("Microsoft.XMLHTTP");
        }
    }

    //the request could still be null if neither ActiveXObject
    //initializations succeeded
    if(request){

	    request.onreadystatechange= function () {
	        if (request.readyState == 4) {
		        if(request.status == 200){
			    	handleJson(request.responseText);
			}
	        }
	    };

    	    request.open(reqType,url,asynch);
	    request.setRequestHeader("Content-Type","application/x-www-form-urlencoded; charset=UTF-8");
            // request.setHeader("Cache-Control", "no-cache");
	    request.send(null);
    }  else {
        alert("Your browser does not permit the use of all of this application's features!");
    }
}

function initLayer(layer)
{
  new Draggable(layer);
}
function showLayer(layer)
{
  document.getElementById('popupMask').style.display = "block";
  document.getElementById(layer).style.display = "block";
}

function hideLayer(layer)
{
  document.getElementById(layer).style.display = "none";
  document.getElementById('popupMask').style.display = "none";
}