How to enable flash debugger ?

I download the latest flash content manager debugger and installed it on my snow leopard apple mac book pro but I can not make run the debugger (of eclipse). When i go in firefox or safari, and I right click on a flash object.

The contextual menu pop up and show me a 'Debugger'  item that is grayed...!! Anyone know why I cannot run the debugger of flash ??? any tips ?? Please help !!