Hello,
When you press the ENTER key or click on the "..." button to select an input from a list of attributes for a function panel parameter, a callback function is called to display the dialog box. This callback function is located in a DLL. You must deploy this DLL with your fp file to keep this functionnality.
For more information, please see the "NI LabWindows/CVI Help" in "Using LabWindows/CVI>>Instrument Drivers>>Building Function Panels>>Editing a Function Panel Window>>Customizing Controls".
Best regards,