MPL has two commands on the File menu Save and Save As... that allow you to save your model files. You can also use the shortcuts Ctrl-S and Ctrl-A respectively or press the File Save button in the Toolbar.
You use the Save command when you want to save the file using the current name. When you want to save the file under a different name use the Save As... command. The standard Save As dialog box like the one shown below will then be displayed.
Figure 4.4: The Save As Dialog Box
In the middle of the dialog box is list of the files that are in the current folder. Enter the new filename you want to save as in the File Name input box. You can also save the file by selecting one of the existing filenames in the list of files and then press the Save button.