Cheryl,
Is the mower turning over? If so, it is either a fuel, air or spark issue. If it doesn't turn over, it could be safety switch issue. Is the mower in gear? Is the PTO engaged? Does the seat have safety switch?
If there is no "click" when you turn the key, it could be a bad ground, a bad starter soleniod or the starter itself.
Good Luck!
Gunny63
June 2010
Automatic Answer
While you wait for answers, we may have found some information which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix lawn mowers.