I have a drop list in cell a1. with information in cell b1. is there a way i can clear the contents of cell b1 if the value in a1 is changed.

i cant have it as a formula ie in cell b1 ..... if(a1="whatever","information","")

i think i will need vba to do it as in e.g

if cell a1 is changed then clear information from cells range a2 to a30...

thanks