The IDL XDISPLAYFILE procedure displays an ASCII text file using a predefined widget interface. To see an example, enter the following statement at the IDL command prompt:
This command displays the current release notes file for your IDL installation in a widget interface.
To display your own text file, create a "Help" button of some sort in your widget interface and configure the button's event handling procedure to call XDISPLAYFILE with the full path to the text file.
See XDISPLAYFILE for more details.