Black layer mask

This question is a little different.  I want to make a black mask on the layer.  I know if you press Alt at the same time as you press layer mask, it's supposed to work.  But I have a problem that I hope only a few people have -- I only have one hand that works.  Normally, I have "sticky keys" on (Windows).  Using sticky keys, most of the "helper" keys work with pushing the helper key (Ctrl, Alt, Shift) and then pushing the mouse (only one push on the mouse works).  But strangely enough, Alt does not work with the layer mask.  I know there are other ways of making the mask black, but could smeone tell Adobe that Alt does not work properly with sticky on AT THAT POINT?  What I am hoping that the right software engineer will realize this and with the stroke of key make the Alt button work with the layer mask.  Thanks.