nový riadok

<div id="myDiv"></div>
<input type="hidden" value="4" id="theValue" />
        <p><input type="button" value="Pridať riadok" onclick="addElement();" /></p>

function addElement() {
  var ni = document.getElementById('myDiv');
  var numi = document.getElementById('theValue');
  var num = parseInt(document.getElementById('theValue').value )+ 1;
  numi.value = num;
  var newdiv = document.createElement('div');
  var divIdName = 'my'+num+'Div';
  newdiv.setAttribute('id',divIdName);
  newdiv.innerHTML = '<p style="margin-right: '5px'; margin-left: '5px'"><input type="hidden" size="2" value="'+num+'" readonly="yes" /></p><input type="text" name="sirka[]" value="" size="5" class="kalkulacia_input" /><p style="margin-right: '5px'; margin-left: '5px'"><input type="text" name="vyska[]" value="" size="5" /></p><input id="otvaranie_id_'+num+'" type="text" name="otvaranie[]" value="" maxlength="40" readonly="yes" class="cia_input" /><input type="button" name="otv" value="vybrať" onclick="NewWindow(\'http://vyber.php?id='+num+'\',\'name\',\'810\',\'540\',\'yes\');return false" /><p style="margin-right: '5px'; margin-left: '5px'"><input type="text" name="ks[]" value="" size="5" class="acia_input" /></p><input id="obrazok_id_'+num+'" type="hidden" name="img_typ[]" size="1" value="" readonly="yes" />';
  ni.appendChild(newdiv);
}

function removeElement(divNum) {
  var d = document.getElementById('myDiv');
  var olddiv = document.getElementById(divNum);
  d.removeChild(olddiv);
}