function show_tab(po_elem) 
{ // 'a' element (child of 'li' element)
  if (!window.$) 
  {
    return false;
  }
  
  po_li = $(po_elem).parent(); // 'li' element

  if (!po_li.hasClass('current')) 
  {
    po_li.siblings().removeClass('current').children('a').attr('href', '#');
    po_li.addClass('current').children('a').removeAttr('href');
  }
}

function updateVehicleType(dlrurl) {

  // used by main search panel on left-hand side

  if (!window.$) {
    return;
  }

  var hs_carsvans = $('#carsVansTab > li.current > a').html();
  var hs_vehicletype;
  var hs_dlr = '';

  if ($('#searchForm input[name=dlr_or_grp_F]:checked').val() != 'G') {
    hs_dlr = $('#searchForm input[name=dlr_or_grp_F]:checked').val();
    document.getElementById('searchForm').action = '/'+dlrurl+'/used-cars';
  } else {
    document.getElementById('searchForm').action = '/used-cars';
  }
  if ($('#searchForm input[name=used_new_F]:checked').val() == 'U') {
    if (hs_carsvans == 'Cars')  {
      hs_vehicletype = 'C'+hs_dlr;
    } else {
      hs_vehicletype = 'V'+hs_dlr;
    }
  } else {
    // 'N'
    if (hs_carsvans == 'Cars')  {
      hs_vehicletype = 'N'+hs_dlr;
    } else {
      hs_vehicletype = 'L'+hs_dlr;
    }
    if ($('#searchForm input[name=dlr_or_grp_F]:checked').val() != 'G') {
      if (hs_carsvans == 'Cars')  {
        document.getElementById('searchForm').action = '/'+dlrurl+'/new-cars';
      } else {
        document.getElementById('searchForm').action = '/'+dlrurl+'/new-vans';
      }
    } else {
      if (hs_carsvans == 'Cars')  {
        document.getElementById('searchForm').action = '/new-cars';
      } else {
        document.getElementById('searchForm').action = '/new-vans';
      }
    }
  }

  var ho_elem   = $('#searchForm input[name=vehicle_type_F]');
  var hs_oldval = ho_elem.val();

  ho_elem.val(hs_vehicletype);

  if (hs_vehicletype != hs_oldval) 
  {
    ho_elem.change();
  }
}

function validate_search_form()
{
  var fromPrice = new Number($('#from_price_F').val());
  var toPrice = new Number($('#to_price_F').val());

  //alert("Testing From: " + fromPrice + " To: " + toPrice);

  if(fromPrice == '')
  {
    fromPrice = 0;
  }

  if(toPrice == '')
  {
    toPrice = 9999999;
  }

  if(fromPrice >= toPrice)
  {
    alert("Invalid price boundaries - the 'From' price must be lower than the 'To' price");
    return false;
  }
  else
  {
    // postcode regex validation will go here
    var postcodeRegex = new RegExp("^([Gg][Ii][Rr] 0[Aa]{2})|((([A-Za-z][0-9]{1,2})|(([A-Za-z][A-Ha-hJ-Yj-y][0-9]{1,2})|(([A-Za-z][0-9][A-Za-z])|([A-Za-z][A-Ha-hJ-Yj-y][0-9]?[A-Za-z])))) {0,1}[0-9][A-Za-z]{2})$");
    var postcode = $('#postcode_F').val();
    
    if(postcode == "Your Postcode" || postcodeRegex.test(postcode))
    {
      return true;
    }
    else
    {
      alert("Please specify a valid UK postcode in order to do a search by location");
      return false;
    }
  }
}