get component null reference

private int mapSelected;
private mainmenu mainMenu;

void Awake() { mainMenu =
GetComponent(); }

void Start() { mapSelected =
mainMenu.champSelected; }

Object reference not set to an instance of an object
introbeforegame.Start ()

what’s wrong?

You need to supply a type to GetComponent. See the documentation.
If the component you want is a script you have created, use that as the type parameter.

e.g. If you named a script “MenuScript”:

mainMenu = GetComponent(MenuScript); // JS
mainMenu = GetComponent<MenuScript>(); // C#

Script 1:

            if (GUI.Button (new Rect (10,175, 220,40), "option1", GUI.skin.GetStyle("button")))
            {
				champSelected = 4;
                Application.LoadLevel ("Harborintro");
            }
            if (GUI.Button (new Rect (10,175, 220,40), "option2", GUI.skin.GetStyle("button")))
            {
				champSelected = 4;
                Application.LoadLevel ("Harborintro");
            }

Script nr2

Load champSelected from script 1 and save it in “mapSelected”