Drop Shadows

I used the Drop Shadow command in Layer Styles to create a drop shadow but the created shadow is to the left of the object as if the light was coming over my right shoulder. How do I change the position of the shadow so that the shadow is on the right side of the image as if the light was coming across my left shoulder toward the object?

Another option after you open the style options dialogue box...use your cursor and move the shadow on the screen anywhere you wish. Be sure to uncheck 'global lighting' if you don't want any other shadows or bevels on your screen to move.