var screenW = 640, screenH = 480;

if (parseInt(navigator.appVersion)>3) {
	screenW = screen.width;
	screenH = screen.height;
} else if (navigator.appName == "Netscape"
    && parseInt(navigator.appVersion)==3
    && navigator.javaEnabled()
   )
{
	var jToolkit = java.awt.Toolkit.getDefaultToolkit();
	var jScreenSize = jToolkit.getScreenSize();
	screenW = jScreenSize.width;
	screenH = jScreenSize.height;
}