private void LoginPasswordInput_Enter(object sender, EventArgs e)
        {
            if (LoginPasswordInput.ForeColor == Color.Gray)
            {
                LoginPasswordInput.Clear();
            }

            LoginPasswordInput.PasswordChar = '*';
            LoginPasswordInput.ForeColor    = Color.White;
            LoginUnderline2.BackColor       = Color.FromArgb(78, 184, 206);
        }
 /*=====================================================*\
 |                         Login                         |
 \*=====================================================*/
 private void LoginUsernameInput_KeyDown(object sender, KeyEventArgs e)
 {
     if (e.KeyCode == Keys.Enter)
     {
         if (LoginUsernameInput.ForeColor != Color.Gray && LoginPasswordInput.ForeColor != Color.Gray)
         {
             if (LoginUsernameInput.Text != "")
             {
                 login();
             }
         }
         else if (LoginPasswordInput.ForeColor == Color.Gray)
         {
             LoginPasswordInput.Focus();
         }
     }
 }