function cent(amount) {
     return (amount == Math.floor(amount)) ? amount + '' : (  (amount*10 == Math.floor(amount*10)) ? amount + '0' : amount);
}

function total(what,number) {
    var grandTotal = 0;
    var grandTotaldph = 0;
    var grandTotalsum = 0;
    
    var num = (document.getElementById('theValue').value -1)+ 2;
    for (var i=1;i<num;i++) {
        if (what.elements['test_' + i + '_4'].value == '')
            what.elements['test_' + i + '_4'].value == '0.00'; // fix for Opera.
        
        what.elements['test_' + i + '_5'].value = (what.elements['test_'+i+'_4'].value - 0) * (what.elements['test_'+i+'_1'].value - 0);
        grandTotal += (what.elements['test_' + i + '_4'].value - 0) * (what.elements['test_' + i + '_1'].value - 0);
    }
    what.grandTotal.value = cent(Math.round(grandTotal*Math.pow(10,2))/Math.pow(10,2));
    what.grandTotaldph.value = cent((grandTotal*0.20));
    what.grandTotalsum.value = cent((what.grandTotal.value *1)+(what.grandTotaldph.value*1));
}

function addElement() {
  var ni = document.getElementById('myDiv');
  var numi = document.getElementById('theValue');
  var num = (document.getElementById('theValue').value -1)+ 2;
  numi.value = num;
  var newdiv = document.createElement('div');
  var divIdName = 'my'+num+'Div';
  newdiv.setAttribute('id',divIdName);
  if (num=='') num='5';
  newdiv.innerHTML = '<table class="noborder"><tr><td style="text-align: center;" width="35">'+num+'</td><td><input style="text-align: center; width: 60px; border: 1px solid #6EB4CD;" type="text" onchange="total(this.form,10);" name="test_'+num+'_1" id="test" /></td><td><input style="margin-left: 5px; width: 113px; border: 1px solid #6EB4CD;" type="text" name="test_'+num+'_2" id="test" size="20" /></td><td><input style="margin-left: 5px; width: 105px; border: 1px solid #6EB4CD;" type="text" name="test_'+num+'_3" id="test" size="18" /></td><td><input style="margin-left: 7px; width: 70px; border: 1px solid #6EB4CD;" type="text" name="test_'+num+'_4" onchange="total(this.form,10);" id="test" size="10" /></td><td><input style="margin-left: 4px; width: 74px; border: 1px solid #6EB4CD;" type="text" name="test_'+num+'_5" id="test" size="10" /></td></tr></table>';
  ni.appendChild(newdiv);
}

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