string comparison?

Ok so here's what i'm trying to do and how i tried to do it....

I have an action that should set ITUNESMEDIATYPE to "Music Video" if the extension is 'm4v' and to "Normal" if the extension is not 'm4v'

This is what i tried

if($eql(%_extension%,m4v),Music Video,Normal)

when run, everything ends up set to "Unknown"

now I'm not understanding why?
does $eql(x,y) not work with strings?
if not what do i use to compare strings?

You've missed putting in a '$' before 'if($eql(%_extension%,m4v),Music Video,Normal)

thanks

i would have never caught that!