Adobe Photoshop CS

I want to record a macro (action) that resizes a picture to 640 x 480 pixels and then saves the picture under the name: "original name - 640 x 480"  When I run the action, it works fine resizing, but it saves the picture under the name of the picture I used to create the macro and not the name of the picture to which I am applying it.  Does anyone know how to do this?