Lokesh from Newmaket has a problem with his concrete driveway not being level. It actually flows water into the house. If you don't want to dig it all up and start over (which sometimes is the cheapest solution), you can actually raise the concrete slab to level it or even slope it away from the house. The process if called pressure grouting or slab jacking. They inject a special clay slurry under the slab which raises the concrete and then it freezes permanently in this new position. Check the price and compare it to a complete replacement job before contracting the work.
Look in the Yellow Pages under Concrete Contractors, or Foundations and call around for slab jacking or pressure grouting services. In the West this service will be listed right in the yellow pages and the process is economical. In the East it is less well known, you will have to seek it out and it is often quite expensive.
In Montreal you can find the modern version of this that works very well, polyurethane injection. After following the lifting of a 12" concrete slab patio for 5 years now, I can recommend the survices of Pure Lift.