在UpdatePanel的内容已经完全加载之后，如何触发回调函数?

I have an ASP.NET UpdatePanel that can contain many images, and I want to execute some javascript whenever the UpdatePanel is updated, but I don't want it to occur until after all of the images are loaded. I've tried setting up my function as a callback via add_endRequest. This will execute the function after the UpdatePanel's asynchronous postback, but it does not wait until all of the images are loaded. Does anyone have any good suggestions on how I can delay the execution of the function until the images have completely loaded?I have an ASP.NET UpdatePanel that can contain