How to reset a configurable joint quaternion?

At the beginning of my scene I need to reset (0,0,0,0) the quaternion value of the targetRotation. First I tried this:

function Start ()

{

 JointSchulter.GetComponent(ConfigurableJoint).targetRotation = Quaternion.Inverse(transform.localRotation);

}

But this couldn't help me, so tried this one:

function Start ()

{ JointSchulter.GetComponent(ConfigurableJoint).targetRotation = Quaternion.Set(0.0, 0.0, 0.0, 0.0);
}

Here comes an error.