How to return back to false?

I’m having an issue on simple code. I have a public bool variable that is set to false at runtime. I want to set up an OnClick or Clickable method that, once clicked, switches the variable to true in which I can get it to work fine. The issue that I am having is switching it back to false on a second click. I trued the IPointerClickHandler interface and got nowhere then attempted to use the Input.GetMouseDown function and I still can’t seem to figure it out. Am I going about his the wrong way. How would you guys go about it?

public void Update(){

	if (Input.GetMouseButtonDown (0)) {

		if (!selected) {
	
		}

		selected = true;
	}

}

}

Try this :

public void Update()
{
	if (Input.GetMouseButtonDown (0)) 
	{
		selected = !selected;
		
		/*
		Or the longer version
		
		if (selected)
		{
			selected = false;
		}
		else
		{
			selected = true;
		}
		*/
	}
}