How do I read or send a message? (ICCforMac/Windows)

On the left you find in the 'LINKS' list 'Messages' 
  
When you click this option your messages will show in the center of your interface. On the right of each message you have 3 buttons for Reply, Forward and Delete.
  
Above your list of messages you find a button for a New message and for Refreshing your list of messages.
  
Sending a message: Click on New > Fill in the field for Recipient (username) and write your message in the field below. There is a max. of 300 characters (including spaces).  To send it, press the button 'Send'.