Issue with oncheckchanged in vb.net - webforms

Question

I have a page with many gridviews. They are in 2 columns 5 on the left and 5 on the right. They are exactly the same.
The Gridview for Employment has a template for a checkbox on the far left. When this is checked, it fires the following:
Protected Sub ChckedChanged(ByVal sender As Object, ByVal e As EventArgs)
Dim row As GridViewRow = TryCast((CType(sender, Control)).Parent.NamingContainer, GridViewRow)
Dim key As String = GridView5.DataKeys(row.RowIndex).Value.ToString()
Dim Incomeadapter As New DataSet1TableAdapters.IncomeTableAdapter
Dim tblincome As New DataSet1.IncomeDataTable
tblincome = Incomeadapter.GetData(key)
GridView6.DataSource = tblincome
GridView6.DataBind()
Exit Sub
I have debugged this, and this code for some reason I don't understand is LOOPING around! Why does it does this? The first time around it gets the correct info, but then it goes back around and ruins the binding of the gridview to the tableadapter because the wrong ID was put into the call to the tableadapter funcion. Is it possible that OncheckChanged event does not work well with the onclick event? I'm using javascript to make sure that only 1 checkbox can be selected on the gridview on the same checkbox :
<div style="overflow-x: scroll; overflow-y: scroll; height: 100px; width: 444px">
<asp:GridView ID="GridView5" runat="server" DataSourceID="SqlDataSource5" AutoGenerateColumns="False" CellPadding="2" HorizontalAlign="Center" OnRowDataBound="Gridview5_rowdatabound" DataKeyNames="EmpID" RowStyle-Wrap="False" HeaderStyle-Wrap="False" ShowHeader="False" ShowFooter="True" FooterStyle-BackColor="Black">
<FooterStyle BackColor="Black"></FooterStyle>
<HeaderStyle Wrap="False"></HeaderStyle>
<RowStyle HorizontalAlign="Center" />
<Columns>
<asp:TemplateField ItemStyle-Width="25px" HeaderText="">
<ItemTemplate>
<asp:CheckBox ID="ChkSelect" runat="server" onclick="CheckOne(this)" AutoPostBack="True" OnCheckedChanged="ChckedChanged" />
</ItemTemplate>
</asp:TemplateField>
<script type="text/javascript">
function CheckOne(obj) {
var grid = obj.parentNode.parentNode.parentNode;
var inputs = grid.getElementsByTagName("input");
for (var i = 0; i < inputs.length; i++) {
if (inputs[i].type == "checkbox") {
if (obj.checked && inputs[i] != obj && inputs[i].checked) {
inputs[i].checked = false;
}
}
}
}
</script>
Rather than doing a postback, with this checkbox with autopostback set to true, is there a way to bind the income gridview which is below the employment gridview without a postback? The income gridview has a separate sql table which has the ID of the employer table as a column. The idea is when you check a checkbox on gridview5 (employment) the income gridview below changes to show the income items which are reflected of the employer. There can be multiple types of income for each employer. Any advice greatly appreciated.
' CausesValidation="False" />
' />
I was able to fix the "looping" issue by rewriting the code as follows:
Dim key As String = ""
For Each row As GridViewRow In GridView5.Rows
If row.RowType = DataControlRowType.DataRow Then
Dim chkrow As CheckBox = TryCast(row.Cells(0).FindControl("ChkSelect"), CheckBox)
If chkrow.Checked Then
key = GridView5.DataKeys(row.RowIndex).Value.ToString()
End If
End If
Next
'Dim row As GridViewRow = TryCast((CType(sender, Control)).Parent.NamingContainer, GridViewRow)
Dim Incomeadapter As New DataSet1TableAdapters.IncomeTableAdapter
Dim tblincome As New DataSet1.IncomeDataTable
tblincome = Incomeadapter.GetData(key)
GridView6.DataSource = tblincome
GridView6.DataBind()
It is working correctly, however on every postback the page goes up to the top and this is just not acceptable, so I would like to try it with Ajax and update panels. I'm reading up on this now.