If you go into your page on Dreamweaver and open the Server Behaviors panel, there should be one for the upload behavior you applied. If you double click on that, there is a web images only checkbox that you can check.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.