function OknoObrazek(sirka,vyska,clanek,obrazek) {
	sirka+=15;
	vyska+=90;
	if (sirka<630) {
		sirka=630;
	}
	URL='http://periskop.cz/prilohy/obrazek.php?clanek='+clanek+'&id='+obrazek
	o_sirka=screen.width;
	o_vyska=screen.height;
	if((sirka<o_sirka-15)&&(vyska<o_vyska-70)) { 
		window.open(URL,'','toolbar=no,resizable=yes,scrollbars=no,directories=no,width='+String(sirka)+',height='+String(vyska));
	 } else {
	 	if (sirka<o_sirka-15) { 
			window.open(URL,'','toolbar=no,resizable=yes,scrollbars=yes,directories=no,width='+String(sirka)+',height='+String(o_vyska-100));
		 } else {
			window.open(URL,'','toolbar=no,resizable=yes,scrollbars=yes,directories=no,width='+String(o_sirka-40)+',height='+String(o_vyska-100));
		}
	}
}

function OknoVideo(clanek,video) {
	URL='http://periskop.cz/prilohy/video.php?clanek='+clanek+'&id='+video;
	window.open(URL,'','toolbar=no,resizable=yes,scrollbars=no,directories=no,width=630,height=400');
}

function CheckEmail(email,errtxt) {
	if (email=="") {
		if (errtxt!='') alert(errtxt);
		return false;
	} else if (!((email.length > 0) & (email.indexOf("@") > 1 ) & (email.lastIndexOf(".") > email.indexOf("@")))) {
		if (errtxt!='') alert(errtxt);
		return false;
	}
	return true;
}