Hi Daixiwen,
My code was perfect, your site that ate the tabs after i did ctrl+c ctrl+v from Quartus (one more thing to solve). I tried to show you this error of Quartus because i believe that Altera(now Intel) can fix things like that and so get more adepts to use its tools. I never used this forum of Altera but i liked of one thing, you answers very fast! I confess that i did not have a real doubt, but a complain. Good companies receive well the criticisms, but i did not see that here. I hope that Altera could improve that and create a channel to complains and criticisms, and not just create but encourage the users to help Altera to build better tools.