control your mouse by keyboard

i think most of you must be knowing this trick, actually it's not a trick but it's a function of windows xp..... it would be very helpful to someone whose mouse is not working and they've to do an urgent work . it's a very simple trick.
just  press Alt+Left shift key + NumLock.
now i will tell you how to control your mouse..
Use the Numerical pad for controlling the mouse pointer. (eg. 4 to move left 6 to move right....)
5 is for click.
+ is for double click
-  is for right click.

now i would also tell you how to use the on-screen keyboard or in simple language how to use your keyboard using mouse..
To use it go to start-> run and type osk
now you can use it just by clicking on the keys displayed on the on-screen keyboard...