>That expression returns .t. when nCht is odd (2,4,6...) and .f. when nCnt is even (1,3,5...) that way any odd memeber of listbox is selected. You can change that expression to .t. to have all members of listbox selected.

Except that you mixed up words for odd and even; should be "when nCht is even (2,4,6...) and .f. when nCnt is odd (1,3,5...)".

I know I've had problems with such word pairs in foreign languages - in Hungarian, it took me a long time to remember which word meant "narrow" and which meant "wide", which was "is early" and which means "runs late"...