To delete all rows after the value in a cell

[dualaudio454252]

Please, I need some help.
In a read only file I want to have a button that delete every row after the number in A2, for example.
If A2=5, then I use the VBA and delete all lines below 5.
And I can change the number of the last row when I need.
I know how to make the button, just need the code.

I've did a search and find:
http://stackoverflow.com/questions/1...x-in-vba-excel

That's almost what I want.
If someone could help me.