function GetXmlHttpObject()
{
  var xmlHttp=null;
  try
    {
    // Firefox, Opera 8.0+, Safari
    xmlHttp=new XMLHttpRequest();
    }
  catch (e)
    {
    // Internet Explorer
    try
      {
      xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
      }
    catch (e)
      {
      xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
      }
    }
  return xmlHttp;
}

function strona(url)
  {
    var xmlHttp=GetXmlHttpObject()
    xmlHttp.onreadystatechange=function()
      {
      if(xmlHttp.readyState==4)
        {
	document.getElementById('prawo').innerHTML=xmlHttp.responseText;
        }
      }
    xmlHttp.open("GET",url,true);
    xmlHttp.send(null);
  }