Nested Repeater Issue

I have a prb in editable multiple nested repeater, icouldn't get the control when swiping the repeater correspondingly,is there any way to solve this,plz assist me as soon as possible

My Code Follows......

Protected Sub AddPiTrans(ByVal sender As Object, ByVal e As EventArgs)

If txtJobSerialNo.Text = String.Empty Then

Dim message As String = "alert('Enter Job Serial No !!')"

ScriptManager.RegisterClientScriptBlock(TryCast(sender, Control), Me.GetType(), "alert", message, True)

txtJobSerialNo.Focus()

Exit Sub

End If

For Each rptmaster As RepeaterItem In RptPIMaster.Items -------------------------------------First Repeater Control-------------------------------------

Dim rptPITransItem As Repeater = TryCast(rptmaster.FindControl("RptPITrans"), Repeater) -------------------------------------Second Repeater Control-------------

Dim hdinPinNoTrans = TryCast(rptPITransItem.FindControl("hdinPinNo"), Label).Text

Dim dropdownItemName = TryCast(rptPITransItem.FindControl("ddlItemName"), DropDownList).SelectedItem.Text

Dim textBoxQuantity = TryCast(rptPITransItem.FindControl("txtQuantityTrans"), TextBox).Text

Dim dropdownPiUnit = TryCast(rptPITransItem.FindControl("ddlPiUnit"), DropDownList).SelectedItem.Text

Dim textAmount = TryCast(rptPITransItem.FindControl("txtAmountTrans"), TextBox).Text

adpEpcgTrans = New OdbcDataAdapter("select * from new_piquotation_trans_copy where Id=0", con)

tblEpcgTrans = New DataTable

adpEpcgTrans.Fill(tblEpcgTrans)

Dim cmdEpcgTrans1Update As New OdbcCommandBuilder(adpEpcgTrans)

If RptPIMaster.Items.Count > 0 Then

Dim NewRecordTrans = tblEpcgTrans.NewRow

NewRecordTrans("jkg_ref_no") = txtJKGRefNo.Text

NewRecordTrans("epcg_job_serial_no") = lblShowJobSerialNo.Text

NewRecordTrans("PI_quotation_no") = hdinPinNoTrans

NewRecordTrans("item_name") = dropdownItemName

NewRecordTrans("quantity") = textBoxQuantity

NewRecordTrans("unit") = dropdownPiUnit

NewRecordTrans("amount") = textAmount

NewRecordTrans("flagForUpdation") = Val(0)

tblEpcgTrans.Rows.Add(NewRecordTrans)

adpEpcgTrans.Update(tblEpcgTrans)

rptPITransItem.DataSource = GetData("Select * from new_piquotation_trans_copy where PI_quotation_no='" & hdinPinNoTrans & "'")

rptPITransItem.DataBind()

End If

End Sub