help me in ISDN card

It can be hard for non native English speakers to get their problem across. Lets try to expand on what your problem is.
What kind of Digium ISDN card have you installed?
When you say it's working now, do you mean that you can make calls out from your extension, or do you mean the driver loads?
I'm pretty sure the problem you are describing above is that if you call in to the Trixbox system, your extension doesn't ring. Is that the problem?
Do you know how to view the live console of Asterisk either from the server or via an SSH connection?
When you make a call in to the system, does the console show any indication that a call has been received?
Did you set up inbound and outbound routes? If not, go find Trixbox without Tears and come back when you've read it.
Do you know where to find the log files? Have a look through these logs, as they are the key to locating your issue.
If the call is making to the Trixbox, you should see that in the logs, and if you follow the logic through, you should end up at the problem. Grab these last 10 or so lines up to the problem and post them.