auto end date when creating a milestone

auto end date when creating a milestone

i am creating milstones for march 2008.
I do: create new milstone, input a start date (21 march 2008), then i have to input the end date .
but the field default value is still TODAY (invalid as before the starting date) and i have to browse the calendar up to march again

much better would it be to have the end date set to 21 march 2008 automaticly as soon as i select the starting date.
thanks
jacopo3001