I bought an Emprex webcam (advertised for Windows/Mac) but it won't work. I tried downloading the 'Macam' driver from the Ecamm website but, basically, I don't know what I'm supposed to do with it. When I open the application, a small window appears but says at the bottom 'No camera selected'. Nothing I try makes any difference. Can anyone help or else suggest another webcam (which I can buy in Britain) which will work without needing to buy any other software etc?