function validate_napiste(frm) {
	if(frm.elements['jmeno'].value == '') {
		alert('Je nutno vyplnit pole JMENO');
		return false;
	}
	if (!check_email(frm.elements['email'].value,'VÁŠ EMAIL')) return false;
	return true;
}

function validate_friend(friendfrm) {
	if(friendfrm.elements['url'].value == '') {
		alert('Nelze poslat odkaz, protože není známá www adresa odkazu.');
		return false;
	}
	
	if(friendfrm.elements['sender_name'].value == '') {
		alert('Je nutno vyplnit pole: VAŠE JMENO');
		return false;
	}
	if (!check_email(friendfrm.elements['sender_email'].value,'VÁŠ EMAIL')) return false;
	if (!check_email(friendfrm.elements['friend_email'].value,'EMAIL KÁMOŠKY')) return false;
	return true;
}



function check_email(email, notice) {
  if (email == '') {
		alert('Je nutno vyplnit pole: ' + notice);
		return false;
	}
	regex = /^((\"[^\"\f\n\r\t\v\b]+\")|([\w\!\#\$\%\&'\*\+\-\~\/\^\`\|\{\}]+(\.[\w\!\#\$\%\&'\*\+\-\~\/\^\`\|\{\}]+)*))@((\[(((25[0-5])|(2[0-4][0-9])|([0-1]?[0-9]?[0-9]))\.((25[0-5])|(2[0-4][0-9])|([0-1]?[0-9]?[0-9]))\.((25[0-5])|(2[0-4][0-9])|([0-1]?[0-9]?[0-9]))\.((25[0-5])|(2[0-4][0-9])|([0-1]?[0-9]?[0-9])))\])|(((25[0-5])|(2[0-4][0-9])|([0-1]?[0-9]?[0-9]))\.((25[0-5])|(2[0-4][0-9])|([0-1]?[0-9]?[0-9]))\.((25[0-5])|(2[0-4][0-9])|([0-1]?[0-9]?[0-9]))\.((25[0-5])|(2[0-4][0-9])|([0-1]?[0-9]?[0-9])))|((([A-Za-z0-9\-])+\.)+[A-Za-z\-]+))$/;
	if(!regex.test(email)) {
		alert('Chybně zadané pole: ' + notice);
		return false;
	}
	return true;
}
  
function otevri_okno(url, width, height) {
	window.open("foto.php?img="+url,"foto","width="+width+",height="+height+",status=1,statusbar=1,toolbar=0,menubar=0,location=0,directories=0,resizable=1,scrollbars=0");
	return false;
}