Detect Mouse Click on GUI Texture (NOT ONGUI)

Hi everyone, I am new to Unity, and Unity Answers.

I am creating a stat selection screen for homework. I am confused about writing a line of code that is probably very simple. I want to detect a click on the GUI Texture without using on Gui if its possible. :)

I have searched for the post that can help me but I do not think anyone is in my situation.

I hope somebody can help! :) Thanks for your time.

 using UnityEngine;
 using System.Collections;
 
 public class StatScript : MonoBehaviour {
     private int[] stats = new int[] {5,5,5,5,5,5};
     private int pointSpend = 25; 
     public GUIText points;
 
     public GUIText strength;
     public GUITexture strengthSpend;
     public GUITexture strengthReturn;
 
     public GUIText stamina;
     public GUITexture staminaSpend;
     public GUITexture staminaReturn;
 
     public GUIText constitution;
     public GUITexture constitutionSpend;
     public GUITexture constitutionReturn;
 
     public GUIText agility;
     public GUITexture agilitySpend;
     public GUITexture agilityReturn;
 
     public GUIText intellegence;
     public GUITexture intelligenceSpend;
     public GUITexture intellegenceReturn;
 
     public GUIText willpower; 
     public GUITexture willpowerSpend;
     public GUITexture willpowerReturn;
 
     public AudioClip selectTone;
 
 
     // Update is called once per frame
     void Update () {
                 points.text = pointSpend.ToString (); 
                 strength.text = stats [0].ToString ();
                 stamina.text = stats [1].ToString ();
                 constitution.text = stats [2].ToString ();
                 agility.text = stats [3].ToString ();
                 intellegence.text = stats [4].ToString ();
                 willpower.text = stats [5].ToString ();
 
         }
 
     void OnMouseUp(){
         audio.PlayOneShot (selectTone);
 
         if (strengthSpend)){
             stats[0]= stats[0] +1;
             pointSpend = pointSpend -1; 
         }
 
         else if  (strengthReturn){
             stats[0]= stats[0] -1;
             pointSpend = pointSpend +1; 
         }
 
         else if  (staminaSpend){
             stats[1]= stats[1] +1;
             pointSpend = pointSpend -1; 
         }
 
         else if  (staminaReturn){
             stats[1]= stats[1] -1;
             pointSpend = pointSpend +1;
         }
 
         else if  (constitutionSpend){
             stats[2]= stats[2] +1;
             pointSpend = pointSpend -1; 
         }
 
         else if  (constitutionReturn){
             stats[2]= stats[2] -1;
             pointSpend = pointSpend +1; 
         }
 
         else if  (agilitySpend){
             stats[3]= stats[3] +1;
             pointSpend = pointSpend -1; 
         }
 
         else if  (agilityReturn){
             stats[3]= stats[3] -1;
             pointSpend = pointSpend +1; 
         }
 
         else if  (intelligenceSpend){
             stats[4]= stats[4] +1;
             pointSpend = pointSpend -1; 
         }
 
         else if  (intellegenceReturn){
             stats[4]= stats[4] -1;
             pointSpend = pointSpend +1; 
         }
 
         else if  (willpowerSpend){
             stats[5]= stats[5] +1;
             pointSpend = pointSpend -1; 
         }
 
         else if  (willpowerReturn){
             stats[5]= stats[5] -1;
             pointSpend = pointSpend +1; 
         }
     }    
 }