Java script to access image size

Hi, I need a few help down here.

I'm doing a project on community website. I am doing it in conventional ASP.
My members are allowed to create communities and they are allowed to upload photographs into the photo gallery in the community.

1. I want to limit user to upload only up to 1MB of image file. How do I filter the file size before the user submit the file upload form? Right now what I do is, user gets to upload using the binary uploader, after the file is in the server, then I check the size. if it is more than 1 mb, delete the file and warn user. However, this wastes bandwith. I want a script that check the file that user is about to upload. if it is > 1MB, don't allow to upload and show alert.

2. I saw this forum and it has (5 member viewing). Anybody can help how to do this in asp? What if the user click away from the forum? how to count down the number of viewing members?

3. When I want to create new thread, it has the panel to edit text (like a text editor in wordpad). How do I get this panel and integrate into my site? (user are abled to write and post their journal as well. It'd be nice to have the text editor panel)

Please help me down here..

Thanks before..