function otevri_kalkulacku() {
  var sirka = screen.availWidth - 10;
  var vyska = screen.availHeight - 28;
  var px = sirka/2-50;
  var py = vyska/2-155;
  window.open('kalkulacka_popup.php', 'kalkulacka', 'width=280,height=140,menubar=no,resizable=no,left='+px+',top='+py)	
}

function vysvit(nazev) {
  var e = document.getElementById(nazev);
  e.className = 'active';
}

function zhasni(nazev) {
  var e = document.getElementById(nazev);
  e.className = '';
}

function printit() {
  window.print();
}

function checkDate(strDate){
  if (strDate.length > 0) {
    var dateregex=/^[ ]*[0]?(\d{1,2})[\/|\.|-](\d{1,2})[\/|\.|-](\d{4,})[ ]*$/;
    var match = strDate.match(dateregex);
    
    if (match){
      var tmpdate = new Date(match[3], parseInt(match[2], 10) - 1, match[1]);
      if (tmpdate.getDate() == parseInt(match[1],10) && tmpdate.getFullYear() == parseInt(match[3], 10) && (tmpdate.getMonth() + 1) == parseInt(match[2], 10)){ 
        return true; 
      } 
      return true;
    }
  }
  return false;
}

function compareDate(date1, date2) {

  if (date1.length > 0 && date2.length > 0) {

    var dateregex=/^[ ]*[0]?(\d{1,2})[\/|\.|-](\d{1,2})[\/|\.|-](\d{4,})[ ]*$/;
    var match1 = date1.match(dateregex);
    var match2 = date2.match(dateregex);
    if (match1 && match2) {
      var tmpdate1 = new Date(match1[3], parseInt(match1[2], 10) - 1, match1[1]);
      var tmpdate2 = new Date(match2[3], parseInt(match2[2], 10) - 1, match2[1]);
    
      if (tmpdate1.getFullYear() > tmpdate2.getFullYear()) {
        return false;
      }

      if (tmpdate1.getMonth() > tmpdate2.getMonth() && tmpdate1.getFullYear() == tmpdate2.getFullYear()) {
        return false;
      }

      if (tmpdate1.getDate() >= tmpdate2.getDate() && tmpdate1.getMonth() == tmpdate2.getMonth() && tmpdate1.getFullYear() == tmpdate2.getFullYear()) {
        return false;
      }

    }
    return true;
  }
  return false; 
}