i bought a Sharp 27R-FS1 recently. My question is stupid but i ask anyway. It is a flat tube TV which is 27". It measures 27" diagnolly, the height and width of the screen are not the same. Does this mean I have a widescreen,pan and scan, or letterbox television????

all tvs are wider than they are tall

that is why it is called "4x3" when they are talking about screen shape (4 wide to the 3 high)

but if a movie fills up the screen it is fullframe

Televisions are not precisely square. They are "squarish". A standard television has an aspect ratio of 1.33:1, meaning that it is 1.33 times wider than tall (this equates to the mathematical ratio of 4:3). Widescreen televisions are 1.78:1 (aka 16:9). All television screen sizes are measured diagonally.

It sounds like you are looking for the correct setting on your DVD player. You should set it to "4:3 letterbox" or possibly just "letterbox".