How is this done?

Click the ‘download picture’ button on the lower left aligned movie.

How do they bring up a save as box for the jpeg? I have searched high and low for a solution on how to make flash save a jpeg to your computer that is stored on a server. I can make it work with a zip file but when I try the jpeg I end up linking to another page.

This is the code I currently use to retrieve a zip file if anyone wants it.

function onMouse1Click(evt:MouseEvent){
    var request:URLRequest = new URLRequest("images/SPR.zip");
    navigateToURL(request);
}
kubek_btn.addEventListener(MouseEvent.CLICK, onMouse1Click);