Vic,The monitor is not capable of displaying anything above its native resolution, although, as Sam points out, you'll be able to use it at lower resolutions if you're prepared to put up with slight distortion of the image.
If you're looking for a 19" TFT monitor I imagine you'd be best searching for one with a native resolution of 1280x1024 rather than 1024x768 - this way your monitor is more 'future-proof' and you'll be able to enjoy high-res games, assuming you've the necessary hardware. Just as 640x480 and then 800x600 slowly died out the same thing may soon happen to 1024x768 as good quality and large monitors become cheaper and more readily available.
-Stephen.