KB31921: How to make auto text {&PromptN&} display as "Null" in exported PDF when PromptN is optional prompt and no answer is selected in MicroStrategy Developer.

In order to display "Null" for auto text {&PromptN&} when PromptN is optional prompt and no answer is selected in Strategy Developer, follow the steps below to achieve this requirement:

• Create an attribute elements prompt with attribute "Category" in Strategy Tutorial Project. Uncheck "Prompt answer required" option to make this prompt be an optional prompt,as shown below:
   
  

• Create a report "test" with attribute "Category","Region" and metric "Cost".
• Add the prompt created in step1 as filter of report "test".
• Create a document with report "test" as dataset and add the report to "Detail Header" section of the document. 
• Add two "Text Field" to "Detail Header" section,one with static text "Null" and another with auto text {&Prompt1&},as shown below:
   
  

• Set "Backstyle" to "Transparent" for static text "Null" and "Opaque" for auto text "{&Prompt1&}" in Property List,as shown below:
   
  

• Put auto text "{&Prompt1&}" on top of the static text "Null" and make it full cover the static text field,as shown below:
   
  

• Export the document to PDF:

• The PDF is shown as below if answering prompt with "Movie":

• The PDF is shown as below if no answer is selected: