Hey Mark,

I 100% agree with this.  When the CodeV to OpticStudio Converter was ported from a compiled DDE to ZPL, Zemax added the BROWSE dialog box; this was a trivial add since it was just a slight variation on the INPUT box but extending ZPL to include an form would be amazing.

Although it might not look pretty, I would use the following logic:

• Create 2 new keywords FORM and ENDFORM;
  • These would act like PLOT and PLOT GO where all the intermediate commands have to be between these 2 keywords
  • A form would only have an OK and Cancel buttons; these would be added automatically by the ZPL
    • The form will be modal
    • OK will continue the ZPL execution with the user inputs as variables
    • Cancel will stop the ZPL execution (same as calling END in the script)
  • If the programmer does not use the ENDFORM keyword, then an error will be thrown in the ZPL PreProcessor
  • A form will only have 2 columns, the left column for the control label and the right column for the control itself (the FFT MTF example above would become twice the height and half the width)
• Only have Label, Checkbox, Combobox, and Textbox with labels
  • Label
    • No control associated with this
    • ex: LABEL “This is an example label”
  • Checkbox
    • Variable will be treated as an integer (no $)
    • Initial value can will be either 0  or non-zero   
    • If 0 then the checkbox is unchecked by default; if any other number then the checkbox is checked by default
    • ex: CHECKBOX “Use Polarization”, pol, 0
  • Combobox
    • Variable will be treated as an integer (no $)
    • Each new drop-down option will be separated by a comma (very similar to the functionality of the $GETSTRINGC() String Keyword)
    • Return values will be the index of the Combobox
    • ex: COMBOBOX "Type", type, "Modulation, Real, Imaginary, Phase, Square Wave"
      • Return would be 0 for “Modulation”...and 4 for “Square Wave”
  • Textbox (used for both numerical values and string values like filenames)
    • Variable will be treated as a string (need $)
    •  Programmer can use SVAL to convert the string to a double value if needed
    • ex: TEXTBOX "Maximum Frequency", maximum_frequency$, "0"

To recreate the FFT MTF settings box, the following code would work:

And the form would look like:

This preserves all the current rules for ZPL and the Pre Processor.  Only 6 new keywords will be needed so the implementation would be straightforward.