Add rich text to custom calculation script in textbox

[mopacmike]

Using custom calculation script to display string based on conditions entered into other form fields.

I have text box configured for rich text and multiple-line display.

How can I add rich text (like a bold font) to certain words within my string that is part of a custom calculation script?  Typical html codes do not seem to have any effect.

[Bernd Alheit]

Look for Span in the Acrobat JavaScript Reference.