Help with composing message

[lensman]

When composing,my message when reaching the edge of the dialogue box,instead of going down to the next line below,it continues on the first line going out of sight of the box.How can I make it go to the line below like when you hit the 'enter' key?Any advice will be very much appreciated.

[Jonboy]

Hi
Not sure but it is happening to me very annoying

[lensman]

Hope somebody can help.