function addRowToTable()
{
  var tbl = document.getElementById('tblSample');
  var lastRow = tbl.rows.length;
  // if there's no header row in the table, then iteration = lastRow + 1
  var iteration = lastRow;
  if(iteration == 26) {
  	alert('Er kunnen maximaal 25 mensen opgegeven worden.')
  } else {
	  var row = tbl.insertRow(lastRow);
	  
	  // left cell
	  var cellLeft = row.insertCell(0);
	  var textNode = document.createTextNode(iteration);
	  cellLeft.appendChild(textNode);
	  
	  // right cell
	  var cellRight = row.insertCell(1);
	  var el = document.createElement('input');
	  el.type = 'text';
	  el.name = 'inp_naam[]';
	  el.id = 'inp_naam[]';
	  el.setAttribute("className","inp_input_small");
	  el.setAttribute("class","inp_input_small");
	  cellRight.appendChild(el);
	  
	  // select cell
	  var cellRightSel = row.insertCell(2);
	  var sel = document.createElement('input');
	  sel.type = 'text';
	  sel.name = 'inp_geboorte[]';
	  sel.id = 'inp_geboorte[]';
	  sel.setAttribute("className","inp_input_small");
	  sel.setAttribute("class","inp_input_small");
	  cellRightSel.appendChild(sel);
  }
}

function removeRowFromTable()
{
  var tbl = document.getElementById('tblSample');
  var lastRow = tbl.rows.length;
  if (lastRow > 2) tbl.deleteRow(lastRow - 1);
}

function MM_validateForm() { //v4.0
  if (document.getElementById){
    var i,p,q,nm,test,num,min,max,errors='',args=MM_validateForm.arguments;
    for (i=0; i<(args.length-2); i+=3) { test=args[i+2]; val=document.getElementById(args[i]);
      if (val) { nm=val.name.substr(4); if ((val=val.value)!="") {
        if (test.indexOf('isEmail')!=-1) { p=val.indexOf('@');
          if (p<1 || p==(val.length-1)) errors+='- '+nm+' moet een geldig emailadres bevatten.\n';
        } else if (test!='R') { num = parseFloat(val);
          if (isNaN(val)) errors+='- '+nm+' must contain a number.\n';
          if (test.indexOf('inRange') != -1) { p=test.indexOf(':');
            min=test.substring(8,p); max=test.substring(p+1);
            if (num<min || max<num) errors+='- '+nm+' must contain a number between '+min+' and '+max+'.\n';
      } } } else if (test.charAt(0) == 'R') errors += '- '+nm+' is verplicht om in te vullen.\n'; }
    } if (errors) alert('Het formulier kan niet verzonden worden:\n'+errors);
    document.MM_returnValue = (errors == '');
} }