move pieces against computer on mac pro

i click a piece i.e pawn from first square and then click on desired square ..i.e e1 to e4.  but it is not responding. how can i make moves? i had already installed java and hit control r to reload it before playing my first computer game.

Hmm, if there are pawns on the first rank there might be other problems.

(Maybe you have to drag and drop instead of clicking twice).

I mean e2 to e4 moving pawn from second rank to forth. I cannot drag an drop on click pad..virtually impossible. When you say drag and drop, it sounds like I need mouse. Correct? I thought click pad works just as we'll, but I now see it is very difficult.

I don't have a mac, so I'm not much use here :)  Sorry.

unfortunate..maybe you are fortunate. nevertheless, i want to make clear that i cannot click twice on mac to play against computer. maybe others will read my comment. I may not doing right with mac pad. maybe i need  keyboard short cuts.