function wopen(wtitle,wwidth,wheight,wname) {
	if (!wwidth) wwidth=500;
	if (!wheight) wheight=535;
	if (typeof usrwin != 'undefined'){
	if (!usrwin.closed){usrwin.close();}}
		usrwin=window.open(wtitle, wname, 'scrollbars=1,top=0,left=0,resizable=0,hotkeys=0,location=0,menubar=0,width='+wwidth+',height='+wheight);
}