D610 video card display on multiple monitors issues

I am hoping someone here can help me.  If I am posting in the wrong forum, please let me know.  I have a Dell D610 laptop that is using an ATI X300 internal video card.  I have my D610 hooked up to an external LG 19 inch LCD monitor that is wide screen.  When  I extend my desktop (the laptop monitor is my primary video display and the LCD monitor is my secondary display) the background image on the laptop monitor is cut off or cropped (sorry about the spelling) on both sides of the image (left side and right side) but the same image on the LCD monitor is centered correctly (I am stretching the image out).  How do I get the two images to look the same.  The image on the laptop monitor was okay until I plugged in the monitor.  I am getting very frustrated with my dual monitor setup.

Edward Letendre