What am I doing wrong in this

I am a beginner and I'm trying to write a code to hide the cursor and lock it in place, but when I test it the cursor is hidden but not locked in place, please help

here is my code

 #pragma strict
 
 function Start () {
     Screen.showCursor = false;
     Screen.lockCursor = true;
 }
 
 function DidShowCursor(){
     Debug.Log("Showing cursor");
 }
 
 function DidHideCursor(){
     Debug.Log("Hiding cursor");
 }    
 
 function DidUnlockCursor(){
     Debug.Log("Unlocking cursor");
     guiTexture.enabled = true;
 }
 
 function DidLockCursor(){
     Debug.Log("Locking cursor");
     guiTexture.enabled = false;
 }    
 
 function OnMouseDown (){
     //lock the cursor
     Screen.lockCursor = true;
     //hide the cursor
     Screen.showCursor = false;
 }    
 
 private var wasLocked = false;
 private var wasShown = true;
 
 function Update () {
     //if escape is pressed, unlock cursor and show cursor
     if (Input.GetButtonDown("Esc"))
         Screen.showCursor = true;
         Screen.lockCursor = false;
         
     if (!Screen.showCursor && wasShown){
         wasShown = true;
         DidShowCursor();
     }
     
     else if (Screen.showCursor && !wasShown){    
         wasShown = false;
         DidHideCursor();    
     }        
     
     if (!Screen.lockCursor && wasLocked){
         wasLocked = false;
         DidUnlockCursor();
     }        
     
     else if (Screen.lockCursor && !wasLocked) {
         wasLocked = true;
         DidLockCursor();
     }
 }