DoQueryBox Does not Work

I'm trying to get a user confirmation when posting a document in the following way:

CloseOrder = DoQueryBox(NStr("en = 'Close this order?'"), QuestionDialogMode.YesNo, 0) <> DialogReturnCode.No;

And receive the following error:

{Document.CustomerOrder.ObjectModule(61,60)}: Variable is not defined (QuestionDialogMode)
CloseOrder = DoQueryBox(NStr("en = 'Close this order?'"), <<?>>QuestionDialogMode.YesNo, 0) <> DialogReturnCode.No; (Verification: Server)
{Document.CustomerOrder.ObjectModule(61,92)}: Variable is not defined (DialogReturnCode)
CloseOrder = DoQueryBox(NStr("en = 'Close this order?'"), QuestionDialogMode.YesNo, 0) <> <<?>>DialogReturnCode.No; (Verification: Server)
{Document.CustomerOrder.ObjectModule(61,15)}: Procedure or function with the specified name is not defined (DoQueryBox)
CloseOrder = <<?>>DoQueryBox(NStr("en = 'Close this order?'"), QuestionDialogMode.YesNo, 0) <> DialogReturnCode.No; (Verification: Server)

You can use DoQueryBox only at client.
Use this code in BeforeClose or BeforeWrite event handlers of the form.

Oh... My mistake. Thanks!