Please help, OnMouseDown function not working.

I’m trying to change a bool value when certain objects (N1,N2 & N3) get clicked on but it is not working. When I click the first object(N1) it DOES change the object color and the variable, as hoped for, but when I get to the second object it does not work anymore. Please check the code to understand:

function OnMouseDown () {

var oneSel = false;
var twoSel = false;
var threeSel = false;


  if (gameObject.tag == "N1") {
  oneSel=true;
  renderer.material.color=Color.red;
  Debug.Log(oneSel);
}

	if ((gameObject.tag == "N2") && (oneSel==true)) {
	twoSel=true;
  	renderer.material.color=Color.red;
	Debug.Log(twoSel);
	}

	  if ((gameObject.tag == "N3") && (twoSel==true)) {
	  threeSel=true;
  	  renderer.material.color=Color.red;
	  Debug.Log(threeSel);
	}
}

The point is to get the objects clicked in sequence…
What am I doing wrong? Someone please help!

I assume the three objects are tagged ‘N1’, ‘N2’ and ‘N3’ in that order. Make ‘oneSel’ ‘twoSel’ and ‘threeSel’ static, and declared at the top of the file (outside of OnMouseDown()):

static var oneSel = false;
static var twoSel = false;
static var threeSel = false;