Applying GUIStyle

I made a code for a basic start menu:

var Style : GUIStyle;

function OnGUI ()
{
GUI.Box(Rect(0, 0, Screen.width, Screen.height), "Survival");
GUI.Button(Rect(165, 70, 80, 40), "Start");
}

I made a variable for the GUIStyle, but how to I actually apply it to the Box?

See the documentation at: http://unity3d.com/support/documentation/ScriptReference/GUI.Box.html

GUI.Box(Rect(0, 0, Screen.width, Screen.height), "Survival", Style);