var firstpart="http://server11.sitewizard.co.uk/sites/dancexpress/images/";
 var maxnum=200
 
 function extractnum() {
  oldsrc=document.getElementById('pic').src
  oldsplit=oldsrc.split("_")
  tmp=oldsplit[1].indexOf(".")
  ournum =oldsplit[1].substring(0,tmp)
  return
 }
 
  function back() {
  extractnum();
  var backnum=ournum-1;
  if (backnum==0) {document.getElementById('pic').src=oldsplit[0] + '_56.jpg'} else { document.getElementById('pic').src=oldsplit[0] + '_' + backnum + '.jpg' }
  }
 
  function forward() {
  extractnum();
  var fornum=1+parseInt(ournum);
  if (fornum==57) { document.getElementById('pic').src=oldsplit[0] + '_1.jpg'}
  else
  {document.getElementById('pic').src=oldsplit[0] + '_' + fornum + '.jpg'}
  }
 
 function initImgView(page) { 
   document.write('<div id=navdiv>')
   var startimgsrc = firstpart + page + "_1.jpg";
    var picwritein ='<div id=picdiv align=center><img id=pic src="' +  startimgsrc + '"></div>';
    document.write(picwritein);
   
      for (var x=0; x<maxnum;x++)  { //preload images
      var preloadsrc=firstpart + page + "_" + x + ".jpg";
      temp = new Image();
      temp.src=preloadsrc;
      //insert our images into page
       tmp=x+1;
      var passedsrc=  "'" + page + "_" + tmp + ".jpg" + "'";
     
      var smallsrc= firstpart + page + "_" + tmp + "small.jpg";
      var tmpsrc= '<span id="' + x + '"><a class=navs href="#" onclick="showpic(' + passedsrc +  ');return false;"><img onerror="loadthisimg(' + x + ')" src="' + smallsrc + '"></a></span>';
      document.write(tmpsrc);
      }
    document.write('</div>');
    };
    
    function loadthisimg(imgref) { 
    document.getElementById(imgref).style.visibility='hidden'; 
    }
    
    function showpic(imgno) {
    var tmp=firstpart + imgno;
    document.getElementById('pic').src=tmp;
    }