BeCareful!: Prepare for War

You have 10 distinct army units in a strategy game online. One of your allies warns you that you will witness an upcoming attack. This attack will simultaneously target 4 areas of your empire. As a commander, you want to evaluate your options. You decide that each area needs at least one army unit and also you have to deploy all of your 10 units no matter what. How many possible deployment options are there?

Note: There was a spacing error in the answer in the database. Problem fixed on 26 July 2012.