jquery to display actual picture

This jQuery should give me thumbnail view of the icjpg.gif but it does not give the actual image that are in the document library. Any idea what I am doing wrong? It just gives me the sharepoint icjpg.gif in bigger size. It's supposed to be working. http://ift.tt/17ZYZ3E

<SCRIPT language=javascript src="http://ift.tt/JN9Wsu" type=text/javascript></SCRIPT> 

<SCRIPT defer type=text/javascript> 
$(document).ready(function(){ 
$("img[src$='icjpg.gif']").each(SetImage); 

}); 
function SetImage() 
{ 

$(this).attr('height','100'); 
$(this).attr('src',$(this).parent().attr('href')); 

} 
</SCRIPT>