welcome every body

i want a lot of times trying to do host but i can't how to do it ??

First you must read the W:A hosting guide.
Second: run regedit.exe(winxp and up), go to HKU\software\team17SoftwareLTD\WormsWorldParty\Net Settings and change key "AdressOverride" from 0 to 1, and check if key "LocalAddress" have your external IP(from www.whatismyip.com).

I've never had a problem hosting in this game, and a lot of people online have told me that I am fortunate. I had no idea hosting was a problem for many players.