How can i make my internet Wierless ?

I'm a new member at at&t company and i had internet before and it was also wierless ,, the problem is i got a new router for at&t company and i already have a Wierless (cisco , link sys) but i don't know how to make it wireless maybe i do !! but i forgot :P! So pleaseee helpp i hate this dumb cable lol