I'm writing a web navigation app for offline browsing, the main page uses 2 frames. I have a menu of links in one frame and a viewer in the other frame. What I need to be able to do is have a default file load in the viewer frame in the event that a link in the link frame contains a bad url. I don't want to use PWS or any other web server to do this. I'm thinking there may be a way to do this with javascript. Basically I need to validate all links before loading them.