function changePictures(category_id,nr)
{
var X;

X=GetXmlHttpObject();

if (X==null)
  {
  alert ("Your browser does not support XMLHTTP!");
  return;
  }
var url_X = 'pictures.php?category_id='+category_id+'&nr='+nr;

X.open("GET",url_X,true);
X.onreadystatechange=function()
  {
  if (X.readyState==4)
    {
    document.getElementById("rightFrame").innerHTML=X.responseText;
    }
  }
X.send(null);

}

function changeCategories(nr)
{
var X;


X=GetXmlHttpObject();

if (X==null)
  {
  alert ("Your browser does not support XMLHTTP!");
  return;
  }
var url_X = 'categories.php?nr='+nr;

X.open("GET",url_X,true);
X.onreadystatechange=function()
  {
  if (X.readyState==4)
    {
    document.getElementById("mainContent").innerHTML=X.responseText;
    }
  }
X.send(null);

var Y;


Y=GetXmlHttpObject();

if (Y==null)
  {
  alert ("Your browser does not support XMLHTTP!");
  return;
  }
var url_Y = 'categories_arrows.php?nr='+nr;

Y.open("GET",url_Y,true);
Y.onreadystatechange=function()
  {
  if (Y.readyState==4)
    {
    document.getElementById("cat").innerHTML=Y.responseText;
    }
  }
Y.send(null);


}



function GetXmlHttpObject()
{
if (window.XMLHttpRequest)
  {
  // code for IE7+, Firefox, Chrome, Opera, Safari
  return new XMLHttpRequest();
  }
if (window.ActiveXObject)
  {
  // code for IE6, IE5
  return new ActiveXObject("Microsoft.XMLHTTP");
  }
return null;
}