// JavaScript Document
function open_centred( page, name, iwidth, iheight, options )
{
	itop = (screen.height - iheight) / 2;
	ileft = (screen.width - iwidth) / 2;
	window.open( page, name, 'height=' + iheight + ',width=' + iwidth + ',top=' + itop + ',left=' +  ileft + ',' + options );
}