So I have got this piece of script:

var sc : HingeJoint;

function Update ()
{
	if(Input.GetButtonUp("Jump"))
	{
		sc = gameObject.AddComponent("hingeJoint");
        //I also tried sc = gameObject.AddComponent("HingeJoint");
	}
}

Don’t work :confused: Can someone correct my script or maybe tell me what am I doing wrong?

try:

    gameObject.AddComponent(HingeJoint);
sc = GetComponent(HingeJoint);

Not sure if you need them on seperate lines, try both.