protected void btn_send_Click(object sender, EventArgs e)
{
string msg = txt_send.Text;
MembershipUser CurrentUser = Membership.GetUser();
Guid senderId = (Guid)CurrentUser.ProviderUserKey;
Guid receiverId = new Guid(ddl_users.SelectedValue);
string message = txt_send.Text;
string date = DateTime.Now.ToString("yyyy-MM-dd");
MessageBLL.AddMsg(senderId, receiverId, message, date);
Response.Redirect($"~/Pages/Users/Message.aspx?messaging={receiverId}");
}