You can edit a message you have posted in a discussion, whether the discussion was started by you or by another user.
To edit a message:
1.        
Move the mouse pointer to the side (left or
right) of the message area until the Edit 
 button appears.
2.        
Click the Edit 
 button.
This activates the message area.
3.        
Edit the text and click 
 or anywhere outside the text area.