What is wrong with my code?

[Spybot]

Hello!
Thank you for your answers.

Using C.Ret's code and I'm getting this as a result: √((c-a)^2+(d-b)^2)
Something happened along the way something broke the code. The little code I posted is just a tiny fraction of a 7k line program I wrote a couple of years ago, everything use to work just fine and then something happened and all my program is broken.