function getObject(index)
{

    var objectArray = new Array (
                 new Array("M13",     "m13x15x5b.jpg",    "tn_m13x15x5b.jpg",   "M13 - Hercules Cluster"),
                 new Array("M51",     "m51x20x31f2b.jpg", "tn_m51x20x31f2b.jpg","M51 - Whirlpool Galaxy"),
                 new Array("M57",     "m57x15x7b2b.jpg",  "tn_m57x15x7b2b.jpg", "M57 - Ring Nebula"),
                 new Array("M1",      "edm1.jpg",         "tn_edm1.jpg",        "M1  - Crab Nebula"),
                 new Array("NGC891",  "edngc891.jpg",     "tn_edngc891.jpg",    "NGC891 in Andromeda"),
                 new Array("NGC7331", "engc7331.jpg",    "tn_engc7331.jpg",     "NGC7331 and NGC7340")
                 );
   return objectArray[index];

}

function getArrayCount()
{
    return 6;
}

function getCurrentImage(i)
{
    var index = parseInt(i);
    return index = index + 1;

}

function getNext(i)
{
   var index = parseInt(i);
   index = index + 1;
   if (index >= getArrayCount()) index = 0;
   return index;
}
function getPrevious(i)
{
   var index = parseInt(i);
   index = index - 1;
   if (index < 0) index = getArrayCount() - 1;
   return index;
}

function getTitle(object) {
    return object[0];
}
function getMainImage(object) {
    return object[1];
}
function getTNImage(object) {
    return object[2];
}
function getCaption(object) {
    return object[3];
}


function retVal(sName)
{

  /*
   get last loc. of ?
   right: find first loc. of sName
   +2
   retrieve value before next &
  
  */
  
  var sURL = new String(window.location);
  var iQMark= sURL.lastIndexOf('?');
  var iLensName=sName.length;
  
  //retrieve loc. of sName
  var iStart = sURL.indexOf('?' + sName +'=') //limitation 1
  if (iStart==-1)
        {//not found at start
        iStart = sURL.indexOf('&' + sName +'=')//limitation 1
		if (iStart==-1)
		   {//not found at end
		    return 0; //not found
		   }   
        }
        
  iStart = iStart + + iLensName + 2;
  var iTemp= sURL.indexOf('&',iStart); //next pair start
  if (iTemp ==-1)
		{//EOF
		iTemp=sURL.length;
		}  
  
  return sURL.slice(iStart,iTemp ) ;
   sURL=null;//destroy String
}