1.(5pt) Convert the Tic Tac Toe game you developed in Homework 4 to an applet. Make sure that your applet can run in a browser, not just in appletviewer or an IDE.

2.(10pt)  [Simple Calculator, Part IV] Continue to work on your calculator application so that all the buttons work properly.

3.(+10pt)  [Simple Calculator, Part V] Put the finishing touch on your calculator and make it as "commercial quality" as possible. In particular, check whether your calculator can properly handle the following cases:

• divided by 0
• square root of a negative number
• backspace a single digit
• multiple decimal points
• leading 0's