PromptPointOptions PromptStatus.Keyword

' set message and keywords
            Dim ppo As PromptPointOptions =
                New PromptPointOptions(vbLf & "Specify cloud starting point or [Arc length/ Second option/Third option]: ", "Arc Second Third")
            Dim lastPoint As Point3d
            ' loop while PromptResult.Status is Keyword
            While True
                Dim ppr As PromptPointResult = ed.GetPoint(ppo)
                If ppr.Status = PromptStatus.Keyword Then 'user choosed an option
                    Select Case ppr.StringResult
                        Case "Arc"
                            Dim pdo As PromptDistanceOptions = New PromptDistanceOptions(vbLf & "Specify arc length: ")
                            pdo.AllowNegative = False
                            pdo.AllowZero = False
                            pdo.DefaultValue = arcDist
                            Dim pdr As PromptDoubleResult = ed.GetDistance(pdo)
                            If pdr.Status = PromptStatus.OK Then
                                arcDist = pdr.Value
                            End If
                            Exit Select
                        Case "Second"
                            ' do what you have to do with "Second" option here
                            Exit Select
                        Case "Third"
                            ' do what you have to do with "Third" option here
                            Exit Select
                    End Select
                ElseIf ppr.Status = PromptStatus.OK Then 'user specified a point
                    lastPoint = ppr.Value
                    Exit While 'exit the loop
                Else 'user cancelled
                    Return
                End If
            End While