Skeleton & Abbrev

[tennis_smith@yahoo.com (Tennis Smith)]

Hi,

I'm trying to build some skeletons for tcl and auto-expand them
with abbrev just like the description here: 

http://www.emacswiki.org/cgi-bin/wiki.pl?SkeletonMode

My definition looks like this:

(define-abbrev tcl-mode-abbrev-table "_if"
"" 'tcl-if)

(define-skeleton tcl-if
  "A simple tcl if skeleton" nil
  \n 
  "if { "
  _
  " } {"
  \n \n
  "} else {"
  \n \n
  "}"
)

(setq skeleton-end-hook nil)


So, when I type in _if in a tcl buffer, it should auto-expand to a new 
"if" statement stub. But, it doesn't do anything. I've turned on abbrev
mode and skeleton, but it doesn't make any difference.  Anyone have any
idea why? 

TIA,
-Tennis