Make this GUI Bigger?

Okay, so I got this script off of the unity website, but how do I make it fill up the whole screen? So here's the script;

/* Example level loader */

function OnGUI () {
    // Make a background box
    GUI.Box (Rect (10,10,100,90), "Menu");

    // Make the first button. If it is pressed, Application.Loadlevel (1) will be executed
    if (GUI.Button (Rect (20,40,80,20), "Play")) {
        Application.LoadLevel (1);

    // Make the second button.
    if (GUI.Button (Rect (20,70,80,20), "Menu")) {
        Application.LoadLevel (0);

This is probably a simple question, but I really need it. And make sure the text is bigger too. Thanks!

All you have to do is set the rectangle values to screen.height and screen.width like so:

Rect(0, 0, Screen.width, Screen.height);

Note when doing this make sure you declare the variable inside the OnGUI function.

For the GUI font you need to import a bigger font size or create a style. This link will help: