I did a google on "widescreen 19" resolution" and it came up with a variety of results, 1440 being the most common. Try looking on the manufacturers website for the native resolution of your monitor - that should tell you for certain.
1280 x 1024 seems to be the native resolution for this monitor click here'+Yuraku+YM19GP+TFT+Monitor+-+8ms?productId=25727 It is probably best to leave at that resolution. The problem may be the widescreen set up. You will need to see if you can change the game options to match. I don't know if this is possible with cod2.