To avoid the tedious task of selecting every row, one by one, I like to save the selection...
...then go into that saved selection's channels palette, where I'll now reload the selection in the mask. With the move tool selected, Shift-DownArrow click (ten spaces at a time) your selection to a masked area, select the eraser tool, and erase over the selection to get rid of that part of the mask. Repeat on down the picture until your selection is complete.

 

Questions? Comments?
e-mail: tom@ahoymatey.com