if(top.location != location)
 {if (document.referrer.subst(11,10) != 'google.com')
   {top.location.href = document.location.href;}
 }

if (document.images)
 {bk = new Image();  bk.src = "back.gif";
  bo = new Image();  bo.src = "backover.gif";}

function Back()
 {if (document.images) document.back.src = bk.src;}

function BackOver()
 {if (document.images) document.back.src = bo.src;}

function GoBack()
 {document.write('<img name=back width=58 height=17'
  + ' src="back.gif" alt="Return to previous page" '
  + 'title= "Return to previous page">');}