Hyundai Repair: Timing, hyundai xg300, crankshaft sensor

Question
My Hyundai xg300 went off timing and the valves bent.  I repaired the cylinder heads & reconnected everything.  After i reconnected the heads i aligned the mark on the crank shaft then after that i aligned the marks on the top pulleys and then connected the belt.  When i went to start the car it didn't want to turn on.  Did i do something wrong?  Thanks.

Answer
It's difficult to say whether you've done anything wrong.  I've seen cases where a timing belt failure will take out a crank sensor from smacking it.  So it's possible you need to replace the crankshaft sensor as well.  

But realistically, since you've had the heads and timing belt off, there are many possibilities of things you may have done wrong.  You'll want to apply normal diagnostic procedures, but pay specific attention to things involved in your repair process that might have caused the problem you're having.

Does the engine crank when you attempt to start the vehicle?
If so, does it crank fast, slow, or normally?

Additionally, I'd like to know how many miles are on the vehicle.  This has little to do with what might be wrong, but I'm interested in knowing how long the timing belt lasted.