Simple expression evaluator

[TonyMUK]

I needed to add a lot of items sold. They are stored in a file as quantity and item price so I needed to calculate each line value and add it to the next. I couldn't see an easy way to do it using the Windows calculator so I wrote this. It explains how it works on the window. It basically takes an expression (e.g. 20*20), calculates it and adds it to the total. Useable operators are */+-^. You can only use one operator at a time with a number either side. I may expand on it if I find other uses but for now it does the job I needed it to do.

[TonyMUK]

New version. Can now add, subtract, multiply or divide the total.