Specific Column's Single Checkbox Checked

Question

Hi, I've a gridview with two columns with checkboxes, In 1st Column I'm checking multiple columns but in 2nd column i just want to check single row, 

<asp:GridView ID="Grid_FeeCategory" Width="100%" CssClass="table" runat="server" AutoGenerateColumns="False">      <Columns>
       <asp:TemplateField Visible="false">
           <ItemTemplate>
                <asp:label ID="LblCatID" runat="server" Text='<%#Eval("CatID")%>' Visible="false" />
           </ItemTemplate>
       </asp:TemplateField>
       <asp:TemplateField>
           <HeaderTemplate>
               <asp:CheckBox ID="checkAll" runat="server" onclick="CheckFirstColumnCheckbox(this);" />
           </HeaderTemplate>
           <ItemTemplate>
                <asp:CheckBox ID="chkRow" runat="server" CssClass="1stColOnly" />
           </ItemTemplate>
       </asp:TemplateField>
       <asp:TemplateField HeaderText="Disc Cat?">
           <ItemTemplate>
               <asp:CheckBox ID="chkIsForDisc" runat="server" onclick="CheckOne(this)" />
           </ItemTemplate>
       </asp:TemplateField>

       <asp:BoundField DataField="CatName" HeaderText="Category" />
       <asp:TemplateField HeaderText="Category Fee" HeaderStyle-Width="125px">
          <ItemTemplate>
               <asp:TextBox ID="txtCat" runat="server" placeholder="Int or Decimal" MaxLength="6" />
          </ItemTemplate>
       </asp:TemplateField>
       </Columns>
   </asp:GridView>

 Above is the grid and below I'm using the jquery functions, the checkone is ambigious it unchecks the other column checkbox too... 

  <script type="text/javascript">
        function CheckFirstColumnCheckbox(objRef) {
            var GridView = objRef.parentNode.parentNode.parentNode;
            var spanList = GridView.getElementsByClassName("1stColOnly");
            for (var i = 0; i < spanList.length; i++) {
                var input = spanList[i].childNodes[0];
                if (objRef.checked && !input.disabled) {
                    input.checked = true;
                }
                else {
                    input.checked = false;
                }
            }
        }
</script>


<script>
    function CheckOne(obj) {
        debugger;
        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>

I just want to check only one checkbox in 2nd column and multiple in 1st column.

thanks in advance.