Move the text in a GUI Button/Box

When you put text (content) into a GUI box or button, the text always appears at the top in the center. How do I alter my code to make the text appear lower down?

GUI.Box(new Rect(400,150,500,300), “Level Complete!”);

Do I put it somewhere after the string “”?
Thanks

Set the coordinates in the Rect( startX, startY, widthX, heightY )