problems with subdivision surface right now im modelling some glasses, and im having a problem with the "subdivision surface" modifier, basically it connects points i don't want to connect...

without subdivision surface:


and with subdivision surface:


here the blenderfile download (mediafire)

i would really appreciate some help :)

edit:
Thanks to Paul,

i got it working by removing the exchange the big face with smaller ones:
You have this huge n-gon (a face with more than 4 vertices) which is a problem when using subdivision surface (and more generally, it's a problem for pretty much everything else too).



From looking at the model I think you had a picture of the profile of the glasses, you then extruded a plane following the profile, then extruded the plane inward to get the thickness and then you just pressed F to fill the remaning hole. That's not going to work. You need quads everywhere. You can either fill each quad manually or try to bridge the loops, but this model is a bit messy.