I already gave a couple links above in post no. 11 . . . I guess you were too busy complaining to notice, much less follow a post. But, don't bother...it's a YouTube link...remember? YouHatem!
Typically there are assorted springs sold in the hardware stores...take your push post with you and find one that just slips over the post with a smidge of room to spare and you may have to cut a coil or two out to let it stand maybe 1/4" taller than the post. Get a couple and experiment. It's not a stupid question.