function get_london_index(town_select) {
    for (i=0;i<town_select.length;i++) {
	if (town_select.options[i].value == london_id) {
	    return town_select.options[i].index;
	}
    }
}

function ShowHide(show_id,hide_id) {
    show = document.getElementById(show_id);
    show.style.display = '';

    hide = document.getElementById(hide_id);
    hide.style.display = 'none';
    if (hide.getElementsByTagName("input").length == 0) {
	hide.getElementsByTagName("select")[0].selectedIndex = 0;
    } else {
	hide.getElementsByTagName("input")[0].value = '';
    }
    return true;
}


function SwitchTownInputs(town_list_id, town_input_id, country_select) {
    if (country_select.options[country_select.selectedIndex].value == uk_country_id) {
	ShowHide(town_list_id, town_input_id);
    } else {
	ShowHide(town_input_id, town_list_id);
    }
}