Exporting with Gmax

Now that I've got gmax up and running, I was following the tutorial by Erwin Horjus. All was fine untill I came to the exporting of the file.
After selecting where I want to save it and typing in a file name, the tutorial say to select " flightsim scenery object (*.MDL) as the type.
The problem is that this type isn't there as an option to select. The onlyoption are Plasma P3D and All Formats.
What have I not done? Anyone
Steve
After selecting where I want to save it and typing in a file name, the tutorial say to select " flightsim scenery object (*.MDL) as the type.
The problem is that this type isn't there as an option to select. The onlyoption are Plasma P3D and All Formats.
What have I not done? Anyone
Steve