Remove key from querystring asp.net

protected void Page_Load(object sender, EventArgs e)
{
    string currentUrl = "http://localhost:39211/?page=2&sort=1&link=12&category=papers";


    string result = RemoveQueryString(currentUrl, "link");
    Response.Write(result);
}


public string RemoveQueryString(string url, string key)
{
    string pattern = key + "=[^&]+&?";
    System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(pattern);
    return regex.Replace(url, "");
}