Force disconnect all users through query analyzer?

Hi,

I am writing a sql script to build a database.  Usually I can just "execute" the entire script which begins with this:
USE [MASTER]
GO
IF EXISTS (SELECT name FROM master.dbo.sysdatabases WHERE name = N'MyDatabase')
      DROP DATABASE [MyDatabase]
GO

This tends to always work when I first open query analyzer.  However after I mess around with the script enough, eventually it stops working with error:
Server: Msg 3702, Level 16, State 4, Line 6
Cannot drop the database 'MyDatabase' because it is currently in use.

No one else is connected to this database.  The only "fix" I know of is to open enterprise manager and go to detach the database (gives me option to punt all users).  I punt the users but do not detach database and then the script can be executed.

So - my question is:  Is there a SQL query that I can place at the top of this script (before DROP DATABASE) that will punt all the users and save me this hassle?

Thanks,
Ian