Masking a jpeg w/ dynamic text?

I’m loading a jpeg w/ loadMovie and creating a text field with createTextField and pulling text dynamically. I’d like to mask the jpeg with the text in the text field so that the jpeg can be seen inside of the text (no matter what it randomly pulls). Is this possible?

Also this site http://www.ourvice.com/ is awesome, anyone know how they achieved the background text (The ‘merging’ together effect?)…