Undo Changes
Clipboard Operations
The Edit menu is used to cut, copy, and paste with the clipboard and to undo changes you have made to your model file.

Figure 4.9: The Edit Menu
Undo - Undo the last change made to model file
Cut - Move the selected text to the clipboard
Copy - Copy the selected text to the clipboard
Paste - Insert text from the clipboard
Delete - Delete the selected text in the model file
Select All - Select all the text in the model file