Piro box add two iframe after asynchronous postback.

when the page loads first time around, the links work as they should, opening in a pirobox .
 
However, if I do a partial postback , the pirobox functionality is lost and clicking on the image inside update panel redirects the entire page rather than opening the target page in the pirobox popup.
 
then i use bellow code on my page load...
Utility.AddScriptEndRequest(this, "SetPiroBox");
 
when page asynchronous postback then show two iframe with image.
how can i remove this. please give me solutions.