please help

hey im currently on a kurok mod team developing left4quake for psp as an animator but was asked to do a model too. i made the model in blender and did the shooting animation but i cant export the model to a quake format or even any format. one side of my model has no faces for some reason but im not sure if that matters. i need to export the model with animation as md2 file but it wont work and i get an error. is there something wrong with my model or blender version?

the missing faces thing seems like it might be a normal problem. In Editing Panel (F9) in edit mode, select “Draw normals” (change NSize if necessary) and make sure they are all pointing out/the way they are supposed to. In Edit mode, “ctrl-n” to recalc normals works on clean meshes, not all the time on complex meshes.
You might also have to apply any modifiers before exporting as well.

ok thanks. what do you mean by adding modifiers though. do you think my model is wrong or what?