Type: String
Default Value: Null
The defaultExt property of the CMDFileSave class contains the default file name extension for the common File Save dialog.
Use this property to specify a default file name extension; for example, .txt or .doc.
When a file with no extension is saved, the extension specified by this variable is automatically appended to the file name.
When you define a value for the defaultExt property, you must also define the filter property value. If the specified defaultExt property value does not exist in the filter string, it defaults to All Files|*.*.