[C#] Add information, maybe text, check boxes to a GUI.Box.

I’m trying to add lines of texts, optional suggestions for a game.
More specifically, Spades. However, I’m having slight trouble with this. I can’t see how to add lines of text, or check boxes to a box in GUI.box. Here’s what I have so far:

public class CameraGUI : MonoBehaviour {
private int menuSelection = -1;
private string[] button=new string[] {
	"Single Player",
	"Multi Player",
	"Leaderboards"};
public GUISkin mainSkin;
static int startB=25;
static int buttonW=425;
static int buttonH=275;
private int windowW=500;
private int windowH=600;
private int screenW=Screen.width;

void OnGUI() {
	GUI.skin=mainSkin;
	menuSelection=GUI.SelectionGrid(new Rect(startB,startB,buttonW,buttonH), menuSelection, button, 1);
	switch(menuSelection) {
	case 0:
		SPOptionsWindow();
		break;
	case 1:
		MPOptionsWindow();
		break;
	case 2:
		LeaderboardsWindow();
		break;
	default:
		//error handling here....
		break;
	}
}
void SPOptionsWindow() {
	GUI.Box(new Rect(screenW*.5f,Screen.height*(.25f/10.0f),windowW,windowH), "Single Player Pre-Start Options");
}
void MPOptionsWindow() {
	GUI.Box(new Rect(screenW*.5f,Screen.height*(.25f/10.0f),windowW,windowH), "Multi Player Pre-Start Options");
}
void LeaderboardsWindow() {
	GUI.Box(new Rect(screenW*.5f,Screen.height*(.25f/10.0f),windowW,windowH), "Leaderboards");
}

}

Hah’, I figured it out. I just used GUI.Window instead of GUI.Box.