neck bend?

How can I make that?

Very carefully! If you insist on doing this, and I don't recommend you do it, play an open string and push forward on the back of the headstock, you'll hear the pitch lower. Be forewarned, this can lead to broken necks, headstocks, and can loosen the neck/body joint on set neck guitars. If you've ever listened to Pat Travers Live album, you hear a bunch of neck bending all thru it.....

I realise your favourite guitarist [Slash-right? ;) ]does this but, if i recall correctly he broke the neck off one of his Gibsons, and injured himself.. I only ever do this on bolt neck guitars [and ones with good straight bolts at that]..,less likely to break,cheaper to fix if they do.

Yeah Slash did hurt himself doin that. He was jammin with Nile Rogers (I think). N he broke the neck off n it hit him on his chin. I read it in an interview with the man himself. Everyone wanted him to go to hospital to get some stitches. But he didn't. He just cleaned it with some JD n got pissed on the rest of it.

English is not my first language so could you tel me what part of the guitar is the headstock?

The headstock is at the end of the neck where the tuners are.

Bill Frisell does it quite a lot too. YOu can usually get away with subtle amounts, as the neck is made to bend a bit anyway, but be very careful. You've really got to ask yoursef how much you need that sound, against how much you can potentially damage your guitar. I VERY occaisionally do it, but only as a slight vibrato for chords at the end of a song. It's really more a look thing though, to do at the end of a big song, and it's kinda like smashing your guitars - how much does look matter when you break your stuff?