GetComponentInChildren question

i have one cube & 6 children attach to Cube Game object & one of these children have "Swing" script attach i want to disable that but there is error coming

i using this script attach to the cube game object

   if (Input.GetButtonDown("Inflated") && (currentform != 2))
        GetComponent("NFmovement").enabled = false;
        GetComponent("IFmovement").enabled = true;
        currentform = 2;

& the error is : No appropriate version of 'UnityEngine.Component.GetComponentInChildren' for the argument list '(String)' was found.

As you can see in the documentation, you can't use strings as arguments with GetComponentInChildren, the way you can with GetComponent. So just leave off the quotation marks. Even with GetComponent, you should leave them off for better performance.