Theme Hospital

In the messages you recive in the fax there are numbers.
Click on "24323" and on the green button.

Return to the game and some cheats are available:
[Ctrl]+[C] : all the equipment
[Shift]+[C] : 10000$
[F11] : lose the level
[F12] : win the level

* To start on a specific level
Use this command line switch: -Lx
Where x is the number of the level you want to start on.

* From another source:
To enter the codes you have to get a fax first.
Press the green ? button that shows up from time to time at the bottom of the screen to get to it.
Then just use the mouse to press the numbers on the fax machine and press the send button.

7827 : After you win the level go to a rat shoot level
24328 : Enable the following codes during gameplay
[Shift]+[C] : Get $2000
[Ctrl]+[C] : All research completed
[Ctrl]+[M] : Skip to the end of the month
[Ctrl]+[Y] : Skip to the end of the year
[Ctrl]+[S] : Doctor with special stills
[Ctrl]+[E] : Makes one emergency
[Shift]+[1] : Extra patient
[Shift]+[I] : Change patients illness

(Information from Cheat Machine)