function ShowUser(user) { 
	var browserVersion = navigator.appVersion;
	var browserVersionNum = parseFloat(browserVersion);
	var cx=0;
	var cy=0;
	if (browserVersionNum >= 4) {
		var availheight=screen.availHeight;
		var availwidth=screen.availWidth;
		cx=(availwidth<400)?0:(availwidth-400)/2;
		cy=(availheight<350)?0:(availheight-350)/2;
	}
	var strFeatures="left="+cx+",top="+cy+",width=400,height=350,resizable=yes,toolbar=no,scrollbars=yes,help=no,status=no";
	res=window.open('/visitka.php?id_user='+user, 'visitka', strFeatures);
	res.focus();
	return(false);
}