easy sql question

Hi
How do you write the sql to empty all the contents of a particular field in a table.

I have a table called customers with name , address , and rep. I want to sql and empty all the rep entries and leave them blank but still retain all the name and addresses


thx, locutus

sSql="Update tablename set field1=NULL where condition"

update customers set rep=Null

Pls make sure that the Field is configured to accept Null values