function zmenObrazek(dataSource, callback)
{ 
	  //opona.style.z-index='50';
        var XMLHttpRequestObject = false; 

        if (window.XMLHttpRequest) {
          XMLHttpRequestObject = new XMLHttpRequest();
        } else if (window.ActiveXObject) {
          XMLHttpRequestObject = new 
            ActiveXObject("Microsoft.XMLHTTP");
        }

        if(XMLHttpRequestObject) {
          XMLHttpRequestObject.open("GET", dataSource); 

          XMLHttpRequestObject.onreadystatechange = function() 
          { 
            if (XMLHttpRequestObject.readyState == 4 && 
              XMLHttpRequestObject.status == 200) { 
                callback(XMLHttpRequestObject.responseText); 
                delete XMLHttpRequestObject;
                XMLHttpRequestObject = null;
            } 
          } 

          XMLHttpRequestObject.send(null); 
        }
}

function callback(text)
{
	 
	  
     document.getElementById("hlavniDIV").innerHTML = text;
	   
	   
      //opona.style.z-index='auto';

}


function velkyIMG(text)
{
	 
	  
     document.getElementById("hlavniDIV").innerHTML = text;
	   
	   
      //opona.style.z-index='auto';

}