mysql to mysqli delete

我正在将MySQL转换为mysqli，我完全卡住了删除

function RemoveItem($itemid) {
    global $db_user, $db_password, $db_database;
    $link_id = mysqli_connect("$db_host", "$db_user", "$db_password", "$db_database");
    if (mysqli_connect_errno()) {
        echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }
    mysqli_query("delete from cart where cookieid = '" . GetCartId() . "'    and itemid = $itemid");
}