Checking an array for duplicate before inserting a new value

Question

Hi all,

I have an array that contains email addresses, before inserting a new address which are being read from a text file into the array how can I check that the address doesn't already exist in the array? I'm trying to make sure there are no duplicates in the array, rather than sorting the array once they are all in, can I check before inserting the address?

Many thanks

PS Using .net 2.0

J