Break My Lock

The rules of the game are simple, but you will have to stretch your brain cells a bit.
1. You have to find break the lock in maximum 10 attempts.
2. The lock combination is a 4-digit number but the digits do not repeat themselves. For example, "3" does not appear twice. Also, first digit cannot be zero.
3. Each time you choose a number and press Submit, you get a response in form of "+X" and "-Y". For example, (+1, -2), which means: a) you found 1 digit and guessed its location correctly; b) you found 2 more digits but they are in the wrong place.

Hint/Example:
If my number is 1234 and you guessed 1982, you will get a response:
+1 for guessing "1" and its location correctly; AND
-1 for guessing "2" but misplacing it.

Results:
If you can do it in less than 6 attempts, you must be a genius or just lucky. If you can do it in 6-8 tries, you are OK but just OK. In 9-10 tries, there is a room for improvement! A big room :)
If you fail in 10 attempts, you must be really unlucky or did not learn how to count yet:)

Good Luck!