Expressions in statements must only be executed for their side-effects.

Hey Ladies and Gentle Fish

I am currently trying to do some basic Javascript coding to change levels and am currently running into this issue.

Expressions in statements must only be executed for their side-effects.

My code is shown: (updated with other people ideas, no error now, but not loading different scenes up.)

#pragma strict
//Attach to Main Camera

var PageNumber : int = 1;
var MaxPageNumber : int = 4;
var MinPageNumber : int = 0;



function OnGUI () {
	GUI.backgroundColor = Color.red;
	if (GUI.Button(Rect(820,505,80,30),"Next")){
		PageNumber = PageNumber + 1;
		print("click");
		if(PageNumber == MaxPageNumber){
			PageNumber = PageNumber - 1;
		}
		else{
		ChangeLevel();
		}
	}
	if (GUI.Button(Rect(500,505,80,30),"Back")){
		PageNumber = PageNumber - 1;
		if(PageNumber == MinPageNumber){
			PageNumber = PageNumber + 1;
		}
		else{
		ChangeLevel();
		}
	}
}

function ChangeLevel() {
	if (PageNumber == 1){
		Application.LoadLevel ("Page 2");
	}
	else if (PageNumber == 2){
		Application.LoadLevel ("Page 3");
	}
	else{
		Application.LoadLevel ("Page 4");
	}
}