Dialog BG Alternance

DialogDisplayer :
Start () :
_BgDialogPNJ = GameObject.Find("overlaySprite-2");
_BgDialogPlayer = GameObject.Find("overlaySprite");
_BgDialogPNJ.renderer.enabled = false;
_BgDialogPlayer.renderer.enabled = false;

Update () -> talking == true :
if(playerSpeaking == true) {
_BgDialogPNJ.renderer.enabled = false;
_BgDialogPlayer.renderer.enabled = true;
}
else {
_BgDialogPNJ.renderer.enabled = true;
_BgDialogPlayer.renderer.enabled = false;
}