Datepicker datasave event - vb.net

Question

I am trying to use windows forms vb.net. Created a simple form with datepicker controls.
These controls are dynamically created. I am using infragistics datepicker here
dtpicker = New UltraDateTimeEditor
dtpicker.Name = "Date" + i.ToString()
dtpicker.MaskInput = "{date} hh:mm"
dtpicker.MaskDisplayMode = MaskMode.IncludeBoth
dtpicker.SpinButtonDisplayStyle = Infragistics.Win.ButtonDisplayStyle.Always
dtpicker.Height = 20
dtpicker.Width = 140
'horizontal
dtpicker.Location = New Point((i * 140), 100)
AddHandler dtpicker.Leave, AddressOf dtpicker_Leave
I have added leave event. But the problem is leave event is fired twice. Please suggest me how to fix or use other correct event.
My data saving logic on leave event looks like this
If Not DBNull.Value.Equals(chkdtFlowPanel.Rows.Item(0).Item("ConveyanceID")) AndAlso Not DBNull.Value.Equals(chkdtFlowPanel.Rows.Item(0).Item("TripID")) Then
ScreenProperty.ARG_ConveyanceID = chkdtFlowPanel.Rows.Item(0).Item("ConveyanceID")
ScreenProperty.ARG_TripID = chkdtFlowPanel.Rows.Item(0).Item("TripID")
Dim prevDatevalue As Object = Nothing
For Each o As Object In UltraPanel1.ClientArea.Controls
If TypeOf (o) Is UltraDateTimeEditor Then
Dim datePicker As UltraDateTimeEditor = o
If prevDatevalue <> Nothing AndAlso datePicker.Value <> Nothing Then
If datePicker.Value < prevDatevalue Then
' Do something Previous value is Lesser
'lblSuccess.Text = "Please verify date entered."
'lblSuccess.ForeColor = Color.Red
Exit Sub
End If
End If
ScreenProperty.ARG_CheckPointTimeID = Convert.ToInt32(datePicker.Tag.Split(","c)(0))
ScreenProperty.ARG_TerminalCheckPointID = Convert.ToInt32(datePicker.Tag.Split(","c)(1))
ScreenProperty.ARG_CheckPointTimeValue = datePicker.Value
Helper.InsertCheckPointTimes(CType(ScreenProperty, KMCommonUITemplates.CUTScreenProperty), Me)
prevDatevalue = datePicker.Value
'lblSuccess.Text = "Data Saved Successfully."
'lblSuccess.ForeColor = Color.Green
End If
Next
'Else
' lblSuccess.Text = "Selected Order does not have Trip/Conveyance created."
' lblSuccess.ForeColor = Color.Red
End If
'Helper.GetCheckPointFlowByTerminalID(CType(ScreenProperty, KMCommonUITemplates.CUTScreenProperty), Me)
ClearText()