Anyone know how to get my taskbar back horizontally instead of vertically??

my son hit some keys on the keyboard, and now my taskbar is vertical on the right side of my monitor instead of horizontally on the bottom. its driving me crazy...ive tried everything i know how to get it to go back, but nothing is working. i goto properties for the taskbar and nothing is there that will help. anyone know how to fix this??? best answer to someone who will help me. tks!