How to reload Chart in VB NET - vb.net

Question

I have this code to load chart in Windows form program. It is placed in button click event handler. When I click the button first time chart is displayed OK. But on second click it will give me error "A chart element with the name 'Series1' could not be found in the 'SeriesCollection'." please see in code.
I'm new to VB not to mention charts and cannot figure out how to fix that so I can click the button any time(s) to reload the chart. Thanks a lot for any advice.
Dim pp As String = "J:\UCP\ApplicationsProgramming\MainDB.accdb"
Dim strConn As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & pp & ";Persist Security Info=False;"
Dim tblFields As String = "SELECT Type, COUNT([Zone]) as CountZone FROM Faults GROUP BY Type "
Dim conn As New OleDbConnection(strConn)
Dim oCmd As New OleDbCommand(tblFields, conn)
Dim oData As New OleDbDataAdapter(tblFields, conn)
Dim ds As New DataSet
conn.Open()
oData.Fill(ds, "Faults")
conn.Close()
'''''''''''''''''''''''''''''
'~~> SET DATA SOURCE <~~'
'''''''''''''''''''''''''''''
Chart1.DataSource = ds.Tables("Faults")
''''''''''''''''''''''''''''''''
'~~> WORKING WITH CHARTAREA <~~'
''''''''''''''''''''''''''''''''
Dim CArea As ChartArea = Chart1.ChartAreas(0)
CArea.BackColor = Color.White
CArea.ShadowColor = Color.Red
CArea.Area3DStyle.Enable3D = True
'~~> Formatting X Axis
CArea.AxisX.MajorGrid.Enabled = False
CArea.AxisX.LabelStyle.Font = New System.Drawing.Font("Arial", _
10.0F, System.Drawing.FontStyle.Italic)
'~~> Formatting Y Axis
CArea.AxisY.MajorGrid.Enabled = False
CArea.AxisY.LabelStyle.Format = ""
CArea.AxisY.Interval = 0.1
''''''''''''''''''''''''''''
'~~> WORKING WITH TITLE <~~'
''''''''''''''''''''''''''''
'~~> Adding a Title
Dim T As Title = Chart1.Titles.Add("Fault Types")
'~~> Formatting the Title
With T
.ForeColor = Color.Black
.BackColor = Color.White
'~~> Setting Font, Font Size and Bold/Italicizing
.Font = New System.Drawing.Font("Arial", 11.0F, System.Drawing.FontStyle.Bold)
.BorderColor = Color.Black
.BorderDashStyle = ChartDashStyle.NotSet
End With
'''''''''''''''''''''''''''''
'~~> WORKING WITH SERIES <~~'
'''''''''''''''''''''''''''''
////// NEXT LINE WILL GIVE FOLLoWING ERROR:
////// "A chart element with the name 'Series1' could not be found in the 'SeriesCollection'." //////////
Dim Series1 As Series = Chart1.Series("Series1") <<<<<<<<<<
'~~> Setting the series Name
Series1.Name = "Fault Types"
'~~> Assigning values to X and Y Axis
Chart1.Series(Series1.Name).XValueMember = "Type"
Chart1.Series(Series1.Name).YValueMembers = "CountZone"
'~~> Setting Font, Font Size and Bold
Chart1.Series(Series1.Name).Font = New System.Drawing.Font("Arial", 10.0F, System.Drawing.FontStyle.Bold)
'~~> Setting Value Type
Chart1.Series(Series1.Name).YValueType = ChartValueType.Double
'~~> Setting the Chart Type for Display
'Chart1.Series(Series1.Name).ChartType = SeriesChartType.Radar
Chart1.Series(Series1.Name).ChartType = SeriesChartType.Pie
'~~> Display Data Labels
Chart1.Series(Series1.Name).IsValueShownAsLabel = True
'~~> Setting label's Fore Color
Chart1.Series(Series1.Name).LabelForeColor = Color.FloralWhite
'~~> Setting label's Format to %age
Chart1.Series(Series1.Name).LabelFormat = "" '"0.0%"
'~~> Setting the location for the chart
Chart1.Size = New System.Drawing.Size(865, 350)

Answer 1

The line Series1.Name = "Fault Types" changes the serie's name.
So, upon click, the next call to Dim Series1 As Series = Chart1.Series("Series1") will fail.
If you use only one serie, you should try Dim Series1 As Series = Chart1.Series(0)