Knoppix 3.6 detected my modem but I can not use it to connect. In the command it says:

Opening device
Error RemoveLock

What does this mean?
Is my modem lock? How can I unlocked?
I have tried it from root command and from user command and I get the same error.

I have tried kppp, tab modem, query which should call the modem and it gives a message that the modem is busy.
I tried the mini terminal to set commands to the modem. It also says that the modem is busy. When I try to reset it, it says modem ready, but when I try to send command to modem, nothing happens.

Is there a way to check why the modem is detected but I can not use it? In windows, I can go to the control panel and click on the modem. Is there something similar to this in linux? Thanks.