multiple choice quiz game, I had error when I would submit/update the score using toolbar, it increases rapidly, can someone tell me my error is? thank you in advance here is my code.

// The position on of the scrolling viewport var scrollPosition : Vector2 = Vector2.zero;

var textfield : GUIText; public var score : int = 0; // Score var guiSkin : GUISkin; //Background

var Question1ToolbarInt : int = 0; var toolbarStrings1 : String[] = ["A", "B", "C", "D"];

var Question2ToolbarInt : int = 0; var toolbarStrings2 : String[] = ["A", "B", "C", "D"];

var Question3ToolbarInt : int = 0; var toolbarStrings3 : String[] = ["A", "B", "C", "D"];

var Question4ToolbarInt : int = 0; var toolbarStrings4 : String[] = ["A", "B", "C", "D"];

function Awake () { textfield = GameObject.Find("ScoreText").GetComponent(GUIText); // ScoreText is the name of the GUIText }

function OnGUI () {

 scrollPosition = GUI.BeginScrollView (Rect (40,40,360,280), //position of the rectangle
     scrollPosition, Rect (-130, 0, 1000, 0)); //1000 is the scrollers limit
     
 GUI.Label (Rect (25, 25, 100, 30), "Label");

 //QUESTION No.1
  Question1ToolbarInt = GUI.Toolbar (Rect (0,160,100,20), Question1ToolbarInt, toolbarStrings1);
  //QUESTION No.2
  Question2ToolbarInt = GUI.Toolbar (Rect (0,180,100,20), Question2ToolbarInt, toolbarStrings2);
  //QUESTION No.3
  Question3ToolbarInt = GUI.Toolbar (Rect (0,200,100,20), Question3ToolbarInt, toolbarStrings3);
  //QUESTION No.4
  Question4ToolbarInt = GUI.Toolbar (Rect (0,220,100,20), Question4ToolbarInt, toolbarStrings4);

  if (Question1ToolbarInt == 1) 
  {
      score++;
      
  }

 if(GUI.Button(Rect(0,240,100,20), "submit")) 
     {
          UpdateScoreText();
     }

 
 // End the scroll view that we began above.
 GUI.EndScrollView ();

}

function UpdateScoreText () { // update textfield with score textfield.text = score.ToString(); }