Ruth is right. Click 'private messages', then click 'new topic', then in the first box click 'find user'. A new window will open and you can enter even just one letter from someone's user name, click 'search' and you will get a drop down list of all users with that letter or combination of letters in their name. Select the one you want and click 'chose the user' and it will pop it into your message box. Piece of cake.