Using Excel 2003. (Australian Date Format).

In Cell B3, I want to type the month and year, eg: April 2008.
In Cell E33, I want to put =B3 so that the result appears as the last day of
the month, eg: 30/04/2008.

In Cell B3, I put a Custom Date Format of mmmm yyyy.
How do I get E33 to return me the last day of the month entered?

Lindy