Chamar form no editor de compras   

Queria saber o que esta mal neste código:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

using ExtensibilityProject4;

using Primavera.Extensibility.BusinessEntities;

using Primavera.Extensibility.BusinessEntities.ExtensibilityService.EventArgs;

using Primavera.Extensibility.Purchases.Editors;

namespace ExtensibilityProject4.Purchases

{

public class UiEditorCompras : EditorCompras

{

private Keys shift;

private Keys keycode;

public override void TeclaPressionada(int KeyCode, int Shift, ExtensibilityEventArgs e)

{

if (keycode == Keys.ControlKey && shift == Keys.D1) {

KeyCode = 0;

shift = 0;

priceCalculatorFrm.show();

}

}

}

}