Public Shared Sub CreateUCS(origin As Point3d, x_axis As Vector3d, y_axis As Vector3d)
        '' Get the current document and database, and start a transaction
        Dim acDoc As Document = _AcAp.Application.DocumentManager.MdiActiveDocument
        Dim acCurDb As Database = acDoc.Database
        
Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()
            '' Open the UCS table for read
            Dim acUCSTbl As UcsTable
            acUCSTbl = acTrans.GetObject(acCurDb.UcsTableId,
            OpenMode.ForRead)
            Dim acUCSTblRec As UcsTableRecord
            '' Check to see if the "New_UCS" UCS table record exists
            If acUCSTbl.Has("New_UCS") = False Then
                acUCSTblRec = New UcsTableRecord()
                acUCSTblRec.Name = "New_UCS"
                '' Open the UCSTable for write
                acUCSTbl.UpgradeOpen()
                '' Add the new UCS table record
                acUCSTbl.Add(acUCSTblRec)
                acTrans.AddNewlyCreatedDBObject(acUCSTblRec, True)
            Else
                acUCSTblRec = acTrans.GetObject(acUCSTbl("New_UCS"),
                OpenMode.ForWrite)
            End If

            acUCSTblRec.Origin = origin 'New Point3d(4, 5, 3)
            acUCSTblRec.XAxis = x_axis 'New Vector3d(1, 0, 0)
            acUCSTblRec.YAxis = y_axis 'New Vector3d(0, 1, 0)
            '' Open the active viewport
            Dim acVportTblRec As ViewportTableRecord
            acVportTblRec = acTrans.GetObject(acDoc.Editor.ActiveViewportId,
            OpenMode.ForWrite)
            '' Display the UCS Icon at the origin of the current viewport
            acVportTblRec.IconAtOrigin = True
            acVportTblRec.IconEnabled = True
            '' Set the UCS current
            acVportTblRec.SetUcs(acUCSTblRec.ObjectId)
            acDoc.Editor.UpdateTiledViewportsFromDatabase()
            '' Display the name of the current UCS
            Dim acUCSTblRecActive As UcsTableRecord
            acUCSTblRecActive = acTrans.GetObject(acVportTblRec.UcsName,
            OpenMode.ForRead)
            _AcAp.Application.ShowAlertDialog("The current UCS is: " &
            acUCSTblRecActive.Name)

            '' Save the new objects to the database
            acTrans.Commit()
        End Using
    End Sub