adding M-tab completion to vm-mail-mode

[matt liggett]

apparently i don't know how to properly specify the keystrokes for
define-key, but i need to know how to add M-tab completion to
vm-mail-mode-map.  i tried to no avail.  thanks and sorry about the
general nature of this question..

     matt liggett       '59 Austin Mini 850 (If only it ran...)
([EMAIL PROTECTED])  '75 Suzuki GT250 (Mutant Chainsaw)
       -= GAT =-        '79 Honda Civic 1200 (Rust Never Sleeps)
d-- -p+ c++(+++) l++ u++ e+ m* s--/ n+(---) h-- f- !g w++ t+ r(-) y++(*)