function black()
{
	document.body.style.backgroundColor = "#000000";
	document.getElementById('alt').style.backgroundImage="url(b_content.gif)"
	document.getElementById('colour').style.color = "#ffffff";
}

function white()
{
	document.body.style.backgroundColor = "#ffffff";
	document.getElementById('alt').style.backgroundImage= "url(w_content.gif)"
	document.getElementById('colour').style.color = "#000000";
}

function openWindow(_url, _name, _width, _height)
{
	_left = (screen.width/2)-(_width/2);
	_top = (screen.height/2)-(_height/2);
	_window = window.open(_url, _name,"height="+_height+",width="+_width+
	",status=0,toolbar=0,menubar=0,location=0,resizable=0,titlebar=0,scrollbars=0,fullscreen=0,top="+
	_top+",left="+_left);
}