C#

public class RelayCommand<T> : ICommand
{
    readonly Action<T> _execute = null;
    readonly Predicate<T> _canExecute = null;

    public RelayCommand(Action<T> execute)
        : this(execute, null)
    {
    }
    public RelayCommand(Action<T> execute, Predicate<T> canExecute)
    {

        if (execute == null)
            throw new ArgumentNullException("execute");

        _execute = execute;
        _canExecute = canExecute;
    }

    public event EventHandler CanExecuteChanged;

    public bool CanExecute(object parameter)
    {
        return _canExecute == null ? true : _canExecute((T)parameter);
    }
    public void Execute(object parameter)
    {
        _execute((T)parameter);
    }
}

private ICommand _PerformanceCommand;
public ICommand PerformanceCommand
{
    get
    {
        if (_PerformanceCommand == null)
        {
            _PerformanceCommand = new RelayCommand<ViewCategory>(p => buttonClicked(ViewCategory.Peformance));
        }
        return _PerformanceCommand;
    }
}

private ICommand _SettingsCommand;
public ICommand SettingsCommand
{
    get
    {
        if (_SettingsCommand == null)
        {
            _SettingsCommand = new RelayCommand<ViewCategory>(p => buttonClicked(ViewCategory.Settings));
        }
        return _SettingsCommand;
    }
}

private void buttonClicked(ViewCategory args)
{ 
}

public void Execute(object parameter)
{
    // parameter is null here
    _execute((T)parameter);
}

public class RelayCommand : ICommand    // No type
public class RelayCommand<T> : ICommand // Accepts a type

 protected void btnUpdate_Click(object sender, EventArgs e)
    {
<big>//this is my problem//</big>
 

        if (Request.QueryString["id"] != null)
        {
            
                        
                 //Declare the connection object
                 SqlConnection Conn = new SqlConnection(ConfigurationManager.ConnectionStrings["MyLocal"].ConnectionString);
 
                 //Make the connection 
                 Conn.Open();
 
                 //Define you query
              
              
                 string sql = "UPDATE [Customer] SET [FirstName] = @FirstName,  [LastName] = @LastName, [Email] = @Email, [Password] = @Password, [Address1] = @Address1, [Address2] = @Address2, [City] = @City, [State] = @State, [zip] = @zip, [Phone] = @Phone, [Fax] = @Fax  WHERE CustomerID=@CustomerID";
                
                 
                 
                 //Declare the Command
                 SqlCommand cmd = new SqlCommand(sql, Conn);
 
                 //Add the parameters needed for the SQL query
                  cmd.Parameters.AddWithValue("@CustomerID", CustomerID);
                   cmd.Parameters.AddWithValue("@FirstName", txtFirstName.Text);
                  cmd.Parameters.AddWithValue("@LastName", txtLastName.Text);
                  cmd.Parameters.AddWithValue("@Email", txtEmailA.Text);
                  cmd.Parameters.AddWithValue("@Password", txtPasswordA.Text);
                  cmd.Parameters.AddWithValue("@Address1", txtAddress1.Text);
                  cmd.Parameters.AddWithValue("@Address2", txtAddress2.Text);
                   cmd.Parameters.AddWithValue("@City", txtCity.Text);
                  cmd.Parameters.AddWithValue("@State", txtState.Text);
                   cmd.Parameters.AddWithValue("@Zip", txtZip.Text);
                  cmd.Parameters.AddWithValue("@Phone", txtPhone.Text);
                   cmd.Parameters.AddWithValue("@Fax", txtFax.Text);
 

 
                 //Execute the query
 
                 cmd.ExecuteNonQuery();
 
                 Conn.Close();
                 Response.Redirect("Customers.aspx");
             
         
 
        }