// JavaScript Document

var IE = navigator.appName.toLowerCase().match("explorer")!=null;

var FIRST_PIC = "1.jpg";
var LAST_PIC = "8.jpg";

function notifyError(errorObject){
  var txt="Si e' verificato un errore.\n\n";
  txt += "name: " + errorObject.name +"\n";
  txt += "message: " + errorObject.message +"\n";
  txt += "function: " + (IE ? getObjectName(notifyError.caller) :  notifyError.caller.name) +"\n";
  txt += "file: " + errorObject.fileName +"\n";
  txt += "line: " + errorObject.lineNumber +"\n\n";  
  alert(txt);
  return true;
}

function viewPrev(arrowEl){
  try{
  	if(arrowEl.src.indexOf("_dis")>0) return;
  	var left = arrowEl.src.indexOf("_left")>0;
  	var prevsEl = arrowEl.parentNode.getElementsByTagName("img");
  	var firstFname=null, lastFname=null;
  	var firstPrevEl=null;
  	for(var i=0; i<prevsEl.length; i++){
  	  var prevEl = prevsEl.item(i);
  	  var url = prevEl.src;
  	  if(url.indexOf("arrow")>=0) continue;
  	  var fname = url.substring(url.lastIndexOf("/")+1);
  	  var prevNum = parseInt( fname.substring(0, url.indexOf(".jpg")) );
  	  var nextFname = (left?prevNum-4:prevNum+4)+".jpg"
      prevEl.src = url.replace(fname, nextFname);
      if(firstFname==null){
        firstFname = nextFname;
        firstPrevEl = prevEl;
      }
  	  lastFname = nextFname;
  	}
  	var leftArrowEl = left ? arrowEl : document.getElementById("arrow_left");
  	var rightArrowEl = !left ? arrowEl : document.getElementById("arrow_right");
  	leftArrowEl.src = "images/arrow_left"+(firstFname==FIRST_PIC?"_dis":"")+".gif";
  	rightArrowEl.src = "images/arrow_right"+(lastFname==LAST_PIC?"_dis":"")+".gif";
  	viewPic(firstPrevEl);
  }catch(e){
  	notifyError(e);
  }
}

function viewPic(prevEl){
  try{
  	var url = prevEl.src;
  	var fname = url.substring(url.lastIndexOf("/"));
  	var picEl = document.getElementById("pic-cont").getElementsByTagName("img").item(0);
  	if(picEl.src.indexOf("/large"+fname)<0) picEl.src = url.replace(fname, "/large"+fname);
  	
  }catch(e){
  	notifyError(e);
  }
}