Display an error message in your survey when an answer is invalid, to ensure that the
    information that users provide is accurate and in an expected format.
    You must purchase a separate license before using survey
    functionality in your application.
    - 
        In the header of Dev Studio, click .
      
- 
        Click the name of a survey.
      
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        Click a question so that it has focus.
      
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        In the Validations section, click the
            Gear icon.
      
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        Define the validation conditions.
        
          - 
            In the Message field, enter text for an error message.
          
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            In the Field list, select a question in your survey.
          
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            In the Value field, enter a value that is the same format as
              the expected answer to the question.
            
              For example, you can enter a positive integer in this field when the answer
                represents years of experience. 
 
              Tip: For more guidance which values you can evaluate in the condition,
                click Select values. 
 
- 
            In the Comparator list, select an operation that compares
              the answer to the value that you provide.
            
              For example, you can verify that the user provides a phone number for each name on
                the emergency contact question page. 
 
- 
            Click OK.
          
 
- 
        Click Save survey.