function popup(url,name,w,h,t,l) {
		if (!w) var w=770;
		if (!h) var h=500;
		if (!t) var t=0;
		if (!l) var l=0;
		window.open( url, name, 'top='+t+', left='+l+', width='+w+', height='+h+', scrollbars=yes, resizable=yes, toolbar=no, menubar=no, status=no, location=no'); 
}

function disableField (f) {	
	f.img.disabled = true;	
	f.position[0].disabled = true;
	f.position[1].disabled = true;
}

function enableField (f) {
	f.img.disabled = false;	
	f.position[0].disabled = false;
	f.position[1].disabled = false;
}