function wop(url, wnd_name, width, height)
{
	w = window.open(
			url, 
			wnd_name, 
			'width=' + width + ', height = ' + height + ', status = no, menubar = no, resizable = no, scrollbars = yes, left = ' + String((screen.width - width) / 2) + ', top = ' + String((screen.height - height)/2)
		);
	w.focus();
	return w;
}

function wop2(url, wnd_name, width, height)
{
	w = window.open(
			url, 
			wnd_name, 
			'width=' + width + ', height = ' + height + ', status = no, menubar = no, resizable = no, scrollbars = no, left = ' + String((screen.width - width) / 2) + ', top = ' + String((screen.height - height) / 2)
		);
	w.focus();
	return w;
}

function fieldview(id) {
if (document.getElementById(id).style.display == 'none') 
{document.getElementById(id).style.display = 'block';} 
else if (document.getElementById(id).style.display == 'block') 
{document.getElementById(id).style.display = 'none';}
}