Brushes

[docquesting]

Due to unsteady hands I have trouble brushing in some things. I have something that I am working on that requires the top edge of the area I am brushing in to be strait. Are there any keyboard short cuts, instead of the mouse for adobe when using the brush? I know for instance in an example to move an image within a layer, you can hold down ctrl and either of the arrow keys to move that image. If someone could tell me if there is away to do this brushing in an area and also how I would be very grateful.

[DOS]

Hold down shift.

Edit: (More specific) Select the brush, click (don't move the mouse, just click) on where you want to use the brush, and hold down shift. This will make the like straight.

[DaveyBoy]

hold down ctrl + select the layer of what u wanna brush in. it will become selected, leave it selected and use the brush, you can't go over the edges now.

[docquesting]

Thanks so much guys I really do appreciate this.