javascript:
for(x=0;x<document.links.length;x++){
  link=document.links[x].href.toLowerCase();
  if(((link.indexOf('.jpg')!=-1)||(link.indexOf('.gif')!=-1)||(link.indexOf('.png')!=-1)||(link.indexOf('.bmp')!=-1))&&(document.links[x].innerHTML.indexOf("<img")!=-1)){
    document.links[x].innerHTML = "<img src='"+document.links[x].href+"'>";
  }
}
return;