how to catch an event when the user delete a cell value

hi,

i would like to know how to catch an event when the user delete a cell value?

when the user delete the entire row i can catch it with the TaskDelete event

when the user enter new value in a cell i can catch it with the TaskChange event.

but when the user hit the "Delete" button on the keyboard  on a cell, no event triggered.

thanks for any help.

Thanks, Sharon.