GÜLMEK and GÜLÜMSEMEK are not two identical verbs that can be interchangeably used.

Gülmek = to laugh

Gülümsemek = to smile

Haklýsýn Alpha, gene de ´gülmek´ kullanmayý tercih ederim

(You are right Alpha, but in spite of it i prefer to use gülmek)

But in this case Foka´s translation is better. (Except for the missing -me)

güzel bir gülümsemen var,daha çok gülümsemelisin

And the microwave goes to Gülbil