private void BtnAdd_Click(object sender, EventArgs e)
 {
     if (TxtPass1.Text == TxtPass2.Text)
     {
         LblInf.Visible = false;
         database db = new database();
         db.Add_user(TxtName.Text, TxtSurname.Text, TxtUsername.Text, TxtPass2.Text);
         foreach (Control objectX in this.Controls)
         {
             if (objectX is TextBox)
             {
                 objectX.Text = "";
             }
         }
     }
     else
     {
         LblInf.Visible = true;
     }
 }