In this exercise, you modify the application from Exercise 2. Use Windows to make a copy of the Workers Solution folder. Rename the copy Workers Solution-Filename.
a. Open the Workers Solution.sln file contained in the Workers Solution-Filename folder. Add a label and a text box to the form. Position both above the existing controls. (You will need to unlock the controls and then reposition the existing ones.) Change the new label’s Text property to &Filename:. Change the new text box’s name to txtFilename. Lock the controls and then reset the tab order.

b. Open the Code Editor window. Code the txtFilename_KeyPress procedure to accept only numbers, letters (uppercase and lowercase), and the Backspace key.
c. Modify the frmMain_FormClosing procedure using the rules shown in Figure 9-40.
d. Save the solution and then start and test the application.