vb- insert row auto after sotring

I would like to insert row automatically, after sorting A to Z in excel, in alphabetical order.
example: if i have at cell B2 the name "Bush"
and at cell B3 the name "Clinton".
I would like that automatically the macro will add a row between them.
so "Bush" will still be at cell B2, but "Clinton"
will change into cell B4!
and an empty row will add into row B3!!!
thank you in advance-
Assaf.