You can do this by having one form with one text field, and then add two instances of yahoo search boss to your page each using the different domains and the same input field.
Then you can just add boss results for each yahoo search boss.
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.