Disable ftp on web browser

Hi there, how can i disable the possibility of accessing hp-ux with ftp in the web browser?
is there any way to do this?

thanks

One word: Firewall

Well, i do have a firewall but only controls the trafic to and from the outside. I do not now if it is possible to disable that possibility, since the firewall is between the frame relay collector and the switch. In fact, the users can only login if they are in the network domain, and inside the network, and i need them to be able to ftp , but not with the web browser.