How to select rows with no duplicate values?

I'll post a example table, just to explain what i want to be done:

-----------
mike 82456 dire@dsfsd.com
steve 88878 dsf@sdfsadf.com
cheff 23423 sdfsf@sdafasdf.com
mike 23423 sdfa@sasd.com
steve 35235 streertert@sdfasfdsd.com
------------

This table is contains information about people, the first column is "userName", second "telephone", third "email"....

So i want to select only rows that have unique "userName", no duplicates. After the selection i want the result to be like this:

--------------
mike 82456 dire@dsfsd.com
steve 88878 dsf@sdfsadf.com
cheff 23423 sdfsf@sdafasdf.com
--------------

..second mike and steve where not selected?

How can i do that?

Every answer will be apreaciated... thanks in advance...

Try:

select distinct userName, telephone, email
from MyTableName

Thank you very much! Distinct helped me all the way...