使用javascript更改iframe的src不显示新页面

In my asp.net application i have a page that has two iframes, and the main page being displayed inside this iframe contains a button. When this button is hit, it calls a javascript function which takes part of the URL and calls a javascript function in the parent window. When the function from the parent is hit, it should change the src of the iframe to a different page - this is not happening. The main iframe has an id ContentIframe and the side iframe has an id LeftIframe. When this is hit - the left side iframe src is changed to nothing, and this works because the left side display does not show what was previously there. The call to change the iframe src for the content frame happens, and the codebehind even loads ( i am able to tell by placing tracepoints in the pageload in the code behind) - but the page is never displayed in the iframe, the previous page with the origional button we clicked is still being displayed. Does anyone know why this would happen? Heres my codeIn my asp.net application i have a page that ha