You are using regular expression validation, but your regular expression doesn't allow a blank option. Can I get FTP access? I can try to update your .js files to account for this scenario.
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.