Since we're dealing with ASP which runs server-side (it will run equally well through nutscrape or IE) I would say VBScript. Client side learning vbscript is a total waste of time since it has limited or no support for nutscrape, but server-side it doesn't matter at all. I would say its worth learning vbscript for the server-side asp because most people writing asp will be using vbscript so its worth becoming accustomed to it. Of course any client-side validation or scripting should be done with Javascript unless you know for sure all clients will be using IE.
The vast majority of people I know who are programming with ASP are doing so with VBscript, I can only think of one guy using javascript for server-side ASP out of all the people I know 🙂