Usage of the on text event will not respond when you type the command.
Example 1:
Joe types !credit
You respond with a notice to Joe saying We owe credits to the following people: Duelist91 - for the "Event" commands, Moshkin_Khan - For the original Bot, Junglebiscui - For the inspiration.
Example 2:
You type !credit
nothing happens
You have two options: 1) Run a second copy of mIRC that acts as a bot, and put the script on the bot, then it'll work when you issue the commands from your client (not the bot).
2) Re-write the script so that it has on input events as well as the on text events.