Determine the game area of the iPhone display when status bar is shown

I have a game for which the iOS status bar is visible. However, when calculating the location of GUI elements, I use the value of Screen.height. However, this value is the height of the entire screen, not the height of the area in which I can draw the GUI elements. (That is, the statusbar takes around 15 pixels away from the drawing area.) Is it possible to determine the height of the graphics area without using a native plugin or making assumptions?