Screen Capture Desktop App

Develop an Adobe Air application that will run on a MAC or PS, requirements: 1. Instal and run on mac or PC 2. starts when the operating system loads but runs in the background screen capture initiates with a keyboard shortcut, one that is not already used by the operating system. I was thinking cntrl + print screen 3. the keyboard shortcut will dim the screen, present a crosshairs for the cursor and when the cursor is dragged the capture part will re-brighten on screen and as the drag occurs the pixel dimensions of the area to be captured is read out to the user 4. the capture is saved to the clipboard as a .jpg and may be pasted into any application, such as e mail clients or design software, it will also automatically save the image to "my documents" Please bid this with time frame.