Usage:
add_text(Edit, Text)
add_text(Edit, Text, FontMask)

Adds the text Text into the edit box Edit with font FontMask.

Edit                 edit box object
Text                 the string that will be added
FontMask      if you like then you can specify the font and the text color which will be used for the added text.
 

Examples:
?-
  ... ,
  Red is font_mask(_,rgb(255,0,0),_,_,_,_,_,_),
  add_text(Edit, "Added Text", Red).