function get_checked_count(elem_name)
{
	check_count = 0;
	if ( document.frm.elements[elem_name].length ){
		for ( i = 0; i < document.frm.elements[elem_name].length; i ++ ){
			if ( document.frm.elements[elem_name][i].checked ){
				check_count ++;
			}
		}
	}
	else if ( document.frm.elements[elem_name].checked ){
		check_count ++;
	}
	return check_count;
}

function something_checked(elem_name)
{
	ret = get_checked_count(elem_name);
	if ( 0 == ret ){
		alert( "１つ以上選択してください。" );
		return false;
	}
	return true;
}

function all_sub_category_check(check, main_category_id, sub_category_count)
{
	for ( i = 1; i <= sub_category_count; i ++ ){
		sub_id = "sub_category"+main_category_id+"_"+i;
		document.frm.elements[sub_id].checked = check;
	}
}

function all_area_check(check, prefix, area_count)
{
	for ( i = 1; i <= area_count; i ++ ){
		id = prefix + i;
		document.frm.elements[id].checked = check;
	}
}