Is it an actual GUITAR, or is it just Mexican STYLE
A Mexican guitar really isn't any different from an acoustic, the primary difference is the strings and body (see ex.):

Regular acoustic:
fat body
steel strings
Mexican:
slim body, often times hand-painted w/ intricate designs
nylon strings (I think..)
edit:
Yes I saw purple's link, I wanted to just post the picture so people wouldn't have to click it to see.
IF that's what the guitar looks like, you just have an ACOUSTIC guitar with a MEXICAN style.
I took Guitar II with Guitar III honors students in highschool my junior year