function ShowWindow(url,name, w, h)
{
  popupWin=window.open(url,name,"height="+h+",width="+w+",screenx=400,screeny=50,status=no,toolbar=no,menubar=no,scrollbars=no");
}
  
  
function IsTextEmpty()
{
  with (document.forms['form1'])
  {
    for (n = 0; n < length; n++)
    {
      if (elements[n].type == 'text' && elements[n].value == '')
      {
        alert ('Wypełnij wszystkie pola tekstowe.');
        return true;
      }
    }
    return false;
  }
}



function IsRadioChecked()
{
  var GroupBox1Checked = false;
  var GroupBox2Checked = false;
  var GroupBox3Checked = false;
  var GroupBox4Checked = false;
  
  with (document.forms['form1'])
  {
    for (n = 0; n < length; n++)
    {
	  if (elements[n].type == 'radio' && elements[n].checked && elements[n].name == 'course')  GroupBox1Checked = true;
	  if (elements[n].type == 'radio' && elements[n].checked && elements[n].name == 'level')   GroupBox2Checked = true;
	  if (elements[n].type == 'radio' && elements[n].checked && elements[n].name == 'place')   GroupBox3Checked = true;
	  if (elements[n].type == 'radio' && elements[n].checked && elements[n].name == 'daytime') GroupBox4Checked = true;
    }
	if (!GroupBox1Checked) {
	  alert ('Wybierz rodzaj kursu.');
	  return false
	}
	if (!GroupBox2Checked) {
	  alert ('Wybierz poziom zaawansowania.');
	  return false
	}
	if (!GroupBox3Checked) {
	  alert ('Wybierz miejsce zajęć.');
	  return false
	}
	if (!GroupBox4Checked) {
	  alert ('Wybierz porę zajęć.');
	  return false
	}
    return true;
  }
}