Twixt and webtv

Hello,

My grandfather accesses this site via webtv. He's been able to play other games, but in his first attempt at Twixt (against me) he was unable to figure out how to make a move. I don't have webtv, so I wasn't much help to him in figuring out what he was doing wrong. (If anything.) I suggested the arrow keys and the tab keys but he said he the tab key did nothing. Can someone with webtv make a suggestion for him on what he needs to do to make a move? Thanks in advance.

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