Internet Restriction

Hi, I have a work computer that currently has windows 98 on it, and I want to restrict access to the internet to all employees but to allow myself to have access to it... I know how to set up two accounts on 98, and I changed some options on the employee account so the internet won't load... but in windows 98 anyone can make up a new user account, and by doing so they can access the internet... so, any tips to restrict access to the internet for others using windows 98? thanks