Width of ButtonEdit/DateEdit/ComboBox
When using
BUTTONEDIT/COMBOBOX/DATEEDIT fields, it is recommended that you 
account for the width of the widget button in addition to the input area.
The problem with BUTTONEDIT, DATEEDIT and COMBOBOX in versions prior to 1.30 is that a field
        [b ] got the width 3, the same width as an edit field with the same
      layout.
For example:
LAYOUT 
GRID
{
  [e  ]
  [b  ]
} 
END 
END 
ATTRIBUTES 
EDIT e=formonly.e; 
BUTTONEDIT b=formonly.b; 
END
In this example, the outer (visual) width of both elements was the same, but the edit portion of
        "b" was much smaller, because the button did not count at all. (In practice
      this meant that on average only one and a half characters of "b" was
      visible). However, you could input 3 characters! This resulted in a
        BUTTONEDIT where only one character was visible and inputting more than one
      character was possible.
Starting with version 1.30, for the Button, the Form Compiler subtracts two character positions
      from the width of
        BUTTONEDIT/COMBOBOX/DATEEDIT. This is
      possible because now the form compiler differentiates the width of the widget from the width
      of the entry part.
In fact, there is no visual difference between version 1.20 and 1.30 regarding this example, but in version 1.30 you can only enter one character, which is visually more correct.
In the example the BUTTONEDIT aligns with the
Edit; that's why the Edit part of       the BUTTONEDIT is
usually still a bit bigger than one character (this depends      
on the button size, but if a button edit is contained by an HBox,
it will get the exact size       of "width" multiplied by the average
character pixel width.
To express  the BUTTONEDIT/COMBOBOX/DATEEDIT layout
more visually, it is possible to specify:
  [e  ]
  [b- ]
the "-" sign marks the end of the edit portion
and the beginning of the button portion ( edit width ="1", widget
width ="3" ).
The two characters are also subtracted for a BUTTONEDIT which
is child of an HBox.
   [b  :]
gets also width="1" , but no widget width, because the HBox stacks the elements horizontally without needing widget width definition.
The two extra characters are only used to show the real size relations more WYSIWYG, and to have the same calculation as in a field without an HBox parent.
  [e1:e2:e3:     ]
  [b1  :b2  :b3  ]
shows that three BUTTONEDIT fields are much larger
than three EDIT fields with the same width.
You can even write:
  [e1:e2:e3:     ]
  [b1- :b2- :b3- ]
or:
  [e1:e2:e3:  ]
  [b1-:b2-:b3-] 
to use slim buttons and
  [e1:e2:e3:        ]
  [b1-  :b2-  :b3-  ]
if one uses large buttons to get the maximum WYSIWYG effect.
Please note that buttons do not grow if two characters "-  " are expanded to
      three characters "- "; the button always computes its size from the image
      used, it's just reserves more space in the form to match the real size.