how do i change my screen name
Click on your name in the upper right hand corner.
Select Edit Adobe profile from the right side of the page
You may have to sign in again
Click on Adobe ID - it is probably highlighted, just click on it
In your "My personal profile" area, you can change your screen name
Follow Stevens answer: that is the way to go.
Your screen name comes from your Adobe ID at Adobe.com.
To change it:
Go to http://www.adobe.com
If you are not yet signed in:
Click on Sign In in the upper right corner (just below the search box)
Sign in with your Adobe ID that you are using in Forums
If you are already signed in:
Click on Welcomd [your name] in the upper right corner
Select My Information
Scroll down to the My Personal Profile section of the page
Fill in a new screen name
Click on the Save My Changes button at the bottom of the Personal Profile section of the page.
You might need to sign out and back into Forums for the forums to pick up your new screen name.