[Kayacterype]

according to Shafi madhab, a father can force her daughter to merry the man he choses for her.

And not only the Shafi'i; also according the Maliki madhhab. But there are various conditions attached to this..

by the way, I have a question, is neccessary to have wali's persmission? for example I am a hanafi and if I wanted to merry someone but my parents forbid me with no valid reasons, can I merry withouth their permission? is their permission neccessary even in this case? what's the opinion of hanafi madhab about this?

According to the Hanafi Madhhab you may marry even without your parents permission if the guy is "compatible" (kufu') with you.

The issue of kufu' regards lineage, Islam, wealth, etc.; see:

http://www.muslimkids.8m.net/NIKAH.htm
Suitability in Marriage: Kafa'a - http://qa.sunnipath.com/issue_view.a...ID=601&CATE=10
Kafa'a - Conjugal suitability - http://qa.sunnipath.com/issue_view.a...=3678&CATE=239
Compatibility in Marriages - Mufti Muhammad Taqi Usmani - http://www.shariahprogram.ca/women-i...arriages.shtml
Kafa'ah (Suitability and Compatibility) in Marriages - http://www.shariahprogram.ca/women-islam/kafaah.shtml
http://www.askimam.org/fatwa/fatwa.p...16b4dceb0448aa
http://www.askimam.org/fatwa/fatwa.p...aef065a0a10735
http://www.askimam.org/fatwa/fatwa.p...bf6e2349b0cd63
http://www.askimam.org/fatwa/fatwa.p...2024077999a09c
http://www.askimam.org/fatwa/fatwa.p...f6d565db2487fc
http://www.askimam.org/fatwa/fatwa.p...30e03bafb2dd92
http://www.askimam.org/fatwa/fatwa.p...24bf6a8f4dfa28
http://www.askimam.org/fatwa/fatwa.p...ff7ae6cc227e30
http://www.askimam.org/fatwa/fatwa.p...5e443bc9802fb7

(the last few links are from the old website but you may have a search on askimam for "kufu'", "kafa'ah", "compatibility" and insha'Allah you'll get many results..