Depending on how much it will cost for repairs, the age and quality of your dishwasher, it might be instead worth investing in a new one. I believe it is about $60 an hour just for the repair person to walk in your door. You can buy a new one for $200 and up.
If you get a new one, don't forget to look for the Energy Star! It may cost a few dollars more, but you will save it in electricity usage pretty quickly, and I think the Energy Stars also use less water. :-D
Also, here's another good advice: buy dishwasher with sprayer on EACH rack. I don't know what it called, but it's a thing that spin and spray water. You'll see it on the bottom, but some do have underneath the top rack. It's better to have two sprayers than one because I have a dishwasher here that did a very poor job because of no sprayer on second rack. Dirts still sitting on top dishes on the top rack. I used to have a dishwasher with two sprayers and it did a beautiful job on cleaning it. I'm going to buy a new one with two sprayers soon.