Using Datagrid Selected Value To Input To Parameter In Stored Procedure

could someone please let me know if i am declaring the parameter wrong or have the wrong VB CODE.  I receive my 3 column headers in my datagrid but the parameter isn't doing anything

STORED PROCEDURE

CREATE PROCEDURE USP_Machcusidsearch

@Machcusid nvarchar  OUTPUT
AS


SELECT     dbo.Machine.machcustomID, dbo.Problem.ProblemDesc, dbo.Request.ReqDate
FROM         dbo.Machine INNER JOIN
                      dbo.Request ON dbo.Machine.machID = dbo.Request.MachID INNER JOIN
                      dbo.Problem ON dbo.Request.ProblemID = dbo.Problem.ProblemID
where machcustomID = @Machcusid
GO

VB.NET CODE

Private Sub LSBmachcusid_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LSBmachcusid.SelectedIndexChanged

SqlDataAdapter2.Fill(DsMachcusidsearch1)

SqlSelectCommand2.Parameters("@Machcusid").Value = LSBmachcusid.SelectedItem.Value

DGstatussearch.DataBind()

End Sub

End Class