xposition=0;xposition = (screen.width - width) / 2;yposition = (screen.height - height) / 2;theproperty= "width=" + width + "," + "height=" + height + "," + "location=0," + "menubar=0,"+ "resizable=1,"+ "scrollbars=0,"+ "status=0," + "titlebar=0,"+ "toolbar=0,"+ "hotkeys=0,"+ "screenx=" + xposition + "," //仅适用于Netscape+ "screeny=" + yposition + &qu