Not exactly sure what you're asking. I looked at your last 3 games; in two of them it looks like you might have wanted to castle to get away from the queen check, but it's against the rules to castle to get out of check. (Also, castling the king across a square which is threatened is illegal too).
As far as the physical act of castling, you select the king with your mouse and move it over two squares. The computer will then automatically hop the rook over for you. If you move the rook with the mouse, it will only count as a rook move and you lose your chance to castle with it.
Open up an analysis board (resources menu at top of your page, select analysis board & editor) if you want to play around with it offline before your next game :-)
i am new to live chess...i have lost 3 games because i did noy castle right on the computer ...how do you do it properly? DENNIS