Help finding a plugin to do this (calculation and display)

Hi everyone,

I have spent the best part of an hour scouring the interwebs and forums looking for a plugin to count the number of times an email submit button is clicked (value “x”) and has a finite number of times (pool) the button can be clicked (value “y”). So…. y – x = z. And I want to display x & z to the user. A subtraction counter if you will – not a countdown.

Something like this
http://darklightlaser.com.au/images/Capture.PNG

Any and all help appreciated.

Cheers!