asp, javascript - hide form after submission

I have a form that posts to a success page. On the success page, I have an option to upload an image. Currently the upload image form posts to a 3rd page. I want to eliminate that 3rd step, basically - because I also give them an option on this 2nd page to go back to the first page and keep all the input for use again. So this is what I want: 1. I would like the image upload page (3rd page) to open in an iframe or via javascript or some method where we stay on the 2nd page and when the upload is successful the form disappears and a message appears instead. the message can be something like: IMAGE UPLOADED I hope that makes sense. I know ASP (which is what I program in), but I'm clueless when it comes to javascript, etc. I stripped down the pages to show the basic info and I can forward that if you think you can help.