Help with script please, boss and destroyed message

I have this script (below) as a sort of lifebar for my boss in game.

All is ok but the one problem I have is the part highlighted in bold.

I use this to instantiate 3d text on screen once the boss is defeated.

The problem I have is that the text keeps reproducing, I think this is because it is in the function Update() part of this code but I don’t know how to seperate it from where it is without messing up the script.

If anyone can give me any pointers or help please do! I’m still very new to coding and trying to pick it up by tutorials and trying out things for myself although my knowledge and vocabulary with scripting is rubbish at the moment

var dead : Texture2D; //dead

var lives : Texture2D; //one life left

var lives2 : Texture2D; //2 lives left

var lives3 : Texture2D; //3 lives left

var lives4 : Texture2D; //4 lives left

var Prefabtargetdestroyed_text : GameObject;

var targetdestroyedtext_holder : GameObject;



static var LIVES = 4;



function Update (){



	switch(LIVES)

	{

	

		case 4:

			guiTexture.texture = lives4;

		break;

			

		case 3:

			guiTexture.texture = lives3;

		break;

		

		case 2:

			guiTexture.texture = lives2;

		break;

		

		case 1:

			guiTexture.texture = lives;

		break;

		

		case 0:

			guiTexture.texture = dead;

			

		**var targetdestroyed_text : GameObject = Instantiate(Prefabtargetdestroyed_text, targetdestroyedtext_holder.transform.position, targetdestroyedtext_holder.transform.rotation);

		Prefabtargetdestroyed_text.transform.parent = targetdestroyedtext_holder.transform;**

		

}

}

A simple solution would be to add a boolean.

public var showText:boolean=true;

//function Update()

if(showText)
{
   //switch(....
   case 0:

       guiTexture.texture = dead;
       **var targetdestroyed_text : GameObject = Instantiate(Prefabtargetdestroyed_text, targetdestroyedtext_holder.transform.position, targetdestroyedtext_holder.transform.rotation);
       Prefabtargetdestroyed_text.transform.parent = targetdestroyedtext_holder.transform;**
       showText=false;
}

Wrap the entire switch or just the contents of case 0 in the boolean, in start make sure it is true. Once the gui texture has been changed, show text is false so we dont keep running the code over and over.