var xmlhttp;
function openGallery(galleryid)
{
xmlhttp=null;
if (window.XMLHttpRequest)
  {// code for Firefox, Opera, IE7, etc.
  xmlhttp=new XMLHttpRequest();
  }
else if (window.ActiveXObject)
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
if (xmlhttp!=null)
  {
  var url="gallery.php?gallery=" + galleryid + "&rand="+Math.random();
  document.getElementById('opengallery').value=galleryid + "_gallery";
  xmlhttp.onreadystatechange=state_Change;
  xmlhttp.open("GET",url,true);
  xmlhttp.send(null);
  }
else
  {
  alert("Your browser does not support XMLHTTP.");
  }
}

function state_Change()
{
if (xmlhttp.readyState==4)
  {// 4 = "loaded"
  if (xmlhttp.status==200)
    {// 200 = "OK"
    document.getElementById('galleryhtml').innerHTML=xmlhttp.responseText;
    var modal_id=document.getElementById('opengallery').value;
    show_modal(modal_id);
    changeImage(1);
    }
  else
    {
    alert("Problem retrieving data:" + xmlhttp.statusText);
    }
  }
}