function ajax_fetch2(datafile) {
 if (!document.all) {
  objXml = new XMLHttpRequest();
  objXml.open("GET","/client/ajax.php?"+datafile,false);
  objXml.setRequestHeader("Content-Type", "text/plain; charset=UTF-8");
  objXml.send(null);
  output=objXml.responseText;
  } 
  else {
   objXml = new ActiveXObject("Microsoft.XMLHTTP");
   //objXml = new ActiveXObject("Msxml2.XMLHTTP"); older version
   objXml.open("GET","/client/ajax.php?"+datafile, false);
   objXml.onreadystatechange=function() {
    if (objXml.readyState==4) {
     output=objXml.responseText;
    }
   }
   objXml.setRequestHeader("Content-Type", "text/plain; charset=UTF-8");
   objXml.send(null);
  }
}

var output="";

function showPhoto(kolejnosc,gwid) {
  ajax_fetch2("a=isPhoto&kolejnosc="+kolejnosc+"&gwid="+gwid);
  var out = JSON.decode(output);
  posY = getScreenCenterY();
  posX = getScreenCenterX();
  if(out[0]=="OK") {
    document.getElementById("photoBox").style.visibility="visible";
    document.getElementById("photoBox").className="photoB1";
    document.getElementById("photoBox").style.top=parseInt(posY-200)+"px";
    document.getElementById("photoBox").style.left=parseInt(posX-250)+"px";
    document.getElementById("photoBox").innerHTML="<span class=\"photoB2\" onclick=\"hidePhoto();return false;\"><img src=\"/client/zamknij.jpg\" border=\"0\"></span><img src=\"/foto/500/"+out[1]+"/"+out[2]+".jpg\" border=\"0\" /><br /><span>"+out[3]+"</span>";

    document.getElementById("shader").style.visibility="visible";
    document.getElementById("shader").className="photoS1";

    document.getElementById("shader").style.top=parseInt(posY-800)+"px";


  }
}


function hidePhoto() {
    document.getElementById("photoBox").style.visibility="hidden";
    document.getElementById("shader").style.visibility="hidden";
    document.getElementById("shader").className="photoS2";
    document.getElementById("photoBox").className="photoB3";
    document.getElementById("photoBox").innerHTML="";
}

function getScreenCenterY() {
  var y = 0;
  y = getScrollOffset()+(getInnerHeight()/2);
  return(y);
}

function getScreenCenterX() {
  return(document.body.clientWidth/2);
}

function getInnerHeight() {
  var y;
  if (self.innerHeight) {
    y = self.innerHeight;
  }
  else if (document.documentElement && document.documentElement.clientHeight) {
    y = document.documentElement.clientHeight;  
  }
  else if (document.body) {
    y = document.body.clientHeight;  
  }
  return(y);
}

function getScrollOffset() {
  var y;
  if (self.pageYOffset) {
    y = self.pageYOffset;
  }
  else if (document.documentElement && document.documentElement.scrollTop) {
    y = document.documentElement.scrollTop;
  }
  else if (document.body) {
    y = document.body.scrollTop;
  }
  return(y);
}