Detect Mouse Click in a GUITexture

Hi, currently I managed to put together a simple script that verifies if the player wants to exit the game, and attached it to a GUITexture, but the problem is that wherever I click in the screen, the script starts working. How can I make that it only works when I click the GUITexture?

Verification Code:

 public class Verification : MonoBehaviour {
 
 private bool exitClicked = false;
 
 void Update()
 {
     if(Input.GetMouseButtonDown(0))
     {
         exitClicked = true;
     }
 }
     
 void OnGUI () 
 {
     if(exitClicked == true)
     {
         GUI.Label(new Rect(Screen.width/2 - 30, Screen.height/2 - 50, 100, 20), "Are You Sure?");
         
         if (GUI.Button (new Rect (Screen.width/2 - 100,Screen.height/2,100,60), "Yes"))
         {
             Application.Quit();
         }
         
         if (GUI.Button (new Rect (Screen.width/2 + 20,Screen.height/2,100,60), "No"))
         {
             exitClicked = false;
         }
     }
 }
 }