function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}

function eraseCookie(name) {
	createCookie(name,"",-1);
}

function processCookie(name){
  var x = readCookie(name);
  if (x) return false
  else return true;
}

function checkform ( form ) {
var res = 0;
for (var i=0;i<document.getElementById('anketa-form').answer0.length;i++) {
if (eval("document.getElementById('anketa-form').answer0[i].checked") == true)
res ++ ;
}
for (var i=0;i<document.getElementById('anketa-form').answer1.length;i++) {
if (eval("document.getElementById('anketa-form').answer1[i].checked") == true)
res ++ ;
}
for (var i=0;i<document.getElementById('anketa-form').answer2.length;i++) {
if (eval("document.getElementById('anketa-form').answer2[i].checked") == true)
res ++ ;
}
for (var i=0;i<document.getElementById('anketa-form').answer3.length;i++) {
if (eval("document.getElementById('anketa-form').answer3[i].checked") == true)
res ++ ;
}
for (var i=0;i<document.getElementById('anketa-form').answer4.length;i++) {
if (eval("document.getElementById('anketa-form').answer4[i].checked") == true)
res ++ ;
}
for (var i=0;i<document.getElementById('anketa-form').answer5.length;i++) {
if (eval("document.getElementById('anketa-form').answer5[i].checked") == true)
res ++ ;
}
if (res == 6) {
  if (processCookie('ANKETA')){
    createCookie('ANKETA','1',365);
    return true;
  } else {
    alert ("Na anketu jste jiz v minulosti odpovedel/a.");
    return false;  
  }
 
 }
else {  alert ("Prosim zaskrtnete odpovedi na vsechny otazky.");
 return false;  
 }
}