function createRequestObject() 
{
  var ro;
  var browser = navigator.appName;
  if(browser == "Microsoft Internet Explorer")
  {
      ro = new ActiveXObject("Microsoft.XMLHTTP");
  }
  else
  {
      ro = new XMLHttpRequest();
  }
  return ro;
}

var http = createRequestObject();
var check;

function sndReq(action, image) 
{
  try {
  	http.open('get', 'fileadmin/uebersichtskarte/imagehover.php?action='+action+'&img='+image);
  	http.onreadystatechange = handleResponse;
 	 http.send(null);
  } catch(e) {
  	//do nothing
  }
}

function handleResponse() 
{
 	try {
	    if(http.readyState == 4)
	    {
	      var response = http.responseText;
	      var update = new Array();
		  
	      if(response.indexOf('|' != -1)) 
	      {
			update = response.split('|');
	        document.getElementById(update[0]).innerHTML = update[1];
	      }
	    }
    } catch(e) {
    	//do nothing
    }
}

//generating a hover effect with css+javascript
function moveBack(where) {
	document.getElementById('overview_map').className = where;
}