var browserVersion;
 
function CheckBrowserVersion()
{
  if (document.all) 
    browserVersion = 1 //IE4   
  else 
    if (document.layers) 
      browserVersion = 2 //NS4 
    else 
      browserVersion = 0 //other 
}

function ShowBigClock(SImage)
{
  if (browserVersion==2)
  {
   document.write('<layer name=pic z-index=-100 left=0 top=70>');
   document.write('<IMG SRC="'+SImage+'">');
   document.write('</layer>');
  }
  else
  {
   document.write('<IMG ID=backimg SRC="'+SImage+'">');
  }
}

CheckBrowserVersion();