this is my gridview code  
<asp:GridView ID="dgAssociatedAttributes" runat="server" AutoGenerateColumns="False" BackColor="White" BorderColor="#999999" BorderStyle="None" BorderWidth="1px" CellPadding="3" GridLines="Vertical" Width="80%">

<FooterStyle BackColor="#CCCCCC" ForeColor="Black" />

<RowStyle BackColor="#EEEEEE" ForeColor="Black" />

<Columns>

          <asp:BoundField DataField="Name" HeaderText="Name" ItemStyle-Width="60%"/>

          <asp:TemplateField HeaderText="Is Required" ItemStyle-HorizontalAlign="Center" ItemStyle-Width="25%" >

         <ItemTemplate>

                  <asp:CheckBox ID="chkIsRequired" runat="server" Checked='<%# Eval("IsRequired") %>' AutoPostBack="true"  OnCheckedChanged="IsRequired_Click" />

          </ItemTemplate>

</asp:TemplateField>

<asp:TemplateField ItemStyle-Width="39%">

     <ItemTemplate >

        <asp:LinkButton ID="lbDelete" runat="server" CausesValidation="false" CommandArgument='<%# Eval("AttributeId") %>' OnCommand="lbDelete_Click" >Delete</asp:LinkButton>

     </ItemTemplate>

</asp:TemplateField>

</Columns>

<PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />

<SelectedRowStyle BackColor="#008A8C" Font-Bold="True" ForeColor="White" />

<HeaderStyle BackColor="#000084" Font-Bold="True" ForeColor="White" />

<AlternatingRowStyle BackColor="#DCDCDC" />
</asp:GridView> 
i want that when i check or uncheck the checkbox it fire a event 
protected void IsRequired_Click(object sender, EventArgs e) 
{
productId = Convert.ToInt32(Request.QueryString["productId"]); 
CheckBox checkbox = sender as CheckBox;
if (checkbox != null) 
{GridViewRow row = checkbox.NamingContainer as GridViewRow; 
int attributeId = 0;
if (row != null) 
{int.TryParse(dgAssociatedAttributes.DataKeys[row.RowIndex].ToString(), out attributeId); 
}if (checkbox.Checked) 
{
db.updateIsRequired(productId, attributeId, true); 
}
else

{
db.updateIsRequired(productId, attributeId, false); 
}
LoadAssociatedAttributes();
} 
}
 
in this code i simply insert the checked value in database through store procedure 
but problem is that i am not able to get the value of "attributeid" . i thought in "EventArgs e" i will b able to get the value like i get it with 

"e.CommandArgument" in delete button click event . but here "e" is returning null 
now how can i get the value of attribute id (the id of row that checkbox is clicked).
plz help me out on this .thanks in advance
Ahtesham

You can easily retrieve the primary key of your data as you are currently doing, but no where in your GridView declaration do I see that you have the DataKeyNames property defined. You must first add the name of your primary key field to this property if you expect to receive a value out of it later.
Thanks, Ed

Microsoft MVP - ASP/ASP.NET

 Make the following changes. 
1. Add an invisible label to that gridview itemtemplate
<ItemTemplate> 
                  <asp:CheckBox ID="chkIsRequired" runat="server" Checked='<%# Eval("IsRequired") %>' AutoPostBack="true"  OnCheckedChanged="IsRequired_Click" />

                  <asp:Label ID="lblId" runat="server"  Visible="false" Text='<%# Bind("TableId")'   />
          </ItemTemplate>
2. Now in checkbox changed event, 
CheckBox chk = (CheckBox)sender; 
GridViewRow gvRow = (GridViewRow)chk.NamingContainer;
Label lblId = (Label)gvRow.FindControl("lblId"); 
string tableid = lblId.Text;
I think you are vb.net programmer. understand the point and make in c#. Use Covnersion tools 
labs.developerfusion.co.uk/convert/csharp-to-vb.aspx
Give a man a fish and you feed him for a day.  Teach a man to fish and you feed him forever.

<script runat="server">
    String mac;                         // This is used to store the TableCell 'userid' within the Gridview
    //String hostName;                  // This is used to store the TableCell 'Host Name' within the Gridview
    String activity;                    // This is used to store the TableCell 'Activity within the Gridveiw
    String buildingNo;                  // This is used to store the TableCell 'Building# within the Gridveiw
    String description2;                // This is stored in the table 'user1' decription.
    String NASEuser;                    // This is used to store UserName to retrieve email form database
    String userEmail;                   // This is used to store the user's Email
    protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        // This will assign the String variables their values pulling them from 
        // the gridview.
 if (e.CommandName == "Update")
        {
            int index = Convert.ToInt32(e.CommandArgument);
            GridViewRow selectedRow = GridView1.Rows[index];
            TableCell userid = selectedRow.Cells[1];
            mac = userid.Text;
            TableCell BuildingNo = selectedRow.Cells[2];
            buildingNo = BuildingNo.Text;
            //TableCell ComputerName = selectedRow.Cells[5];
            //hostName = ComputerName.Text;
            TableCell ActivityName = selectedRow.Cells[3];
            activity = ActivityName.Text;
            description2 = activity + " BLDG " + buildingNo;       //This is inserted into the description column
                                                                   //within the 'user1' table
            TableCell UserName = selectedRow.Cells[6];
            NASEuser = UserName.Text;
        }
    }
    protected void GridView1_RowUpdated(object sender, GridViewUpdatedEventArgs e)
    {
        // First I have to read the table 'macreg' to verify that the 'SqlDataSourceGrid' inserted true or false
        // within the table 'macreg', column 'MACcomplete'.  If the checkbox within the gridview is checked, then
        // enabled will be true, else it will be false.
        try
        {
            String enabled;
            using (SqlConnection cn = new SqlConnection(ConfigurationManager.ConnectionStrings["cs"].ToString()))
            {
                cn.Open();
                SqlCommand cmd = new SqlCommand("INSERT INTO [user1] ([userid], [passwd], [description]) VALUES (@userid, @passwd, @description)", cn);
                SqlCommand cmd2 = new SqlCommand("SELECT * FROM macreg WHERE userid ='" + mac + "'", cn);
                SqlDataReader rdr = cmd2.ExecuteReader();
                rdr.Read();
                enabled = rdr["MACcomplete"].ToString();
                rdr.Close();
                if (enabled == "True")
                {
                    //Parameters
                    cmd.Parameters.Add("@userid", SqlDbType.VarChar, 50);
                    cmd.Parameters.Add("@passwd", SqlDbType.VarChar, 64);
                    cmd.Parameters.Add("@description", SqlDbType.NVarChar, 512);
                    //Values
                    cmd.Parameters["@userid"].Value = mac;
                    cmd.Parameters["@passwd"].Value = mac;
                    cmd.Parameters["@description"].Value = description2;
                    cmd.ExecuteNonQuery();
                }
                cn.Close();
            }
        }
        catch (Exception err)
        {
            ErrorMessageLabel.Text = "ERROR OCCURRED ";
            ErrorMessageLabel.Text += err.Message;
            Response.Write(err);
        }      
    }
</script>
 
    <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSourceGrid"
         CellPadding="4" DataKeyNames="userid" ForeColor="#3B3A60" GridLines="None" PageSize="25" Font-Names="Palatino Linotype"
         BorderColor="#504E6C" BorderStyle="Solid" BorderWidth="1px" HorizontalAlign="Center" Width="100%" OnRowUpdated="GridView1_RowUpdated" OnRowCommand="GridView1_RowCommand" Font-Size="Small" AllowPaging="True" AllowSorting="True">
        <FooterStyle BackColor="#2A203B" Font-Bold="True" ForeColor="White" BorderColor="#2A203B" BorderStyle="Solid" BorderWidth="10px" />
        <Columns>
            <asp:CommandField ShowEditButton="True" EditText="Complete" >
                <ItemStyle ForeColor="#FF8000" />
            </asp:CommandField>
            
            <asp:BoundField DataField="userid" HeaderText="MAC" ReadOnly="True" SortExpression="userid" />
            <asp:BoundField DataField="BuildingNo" HeaderText="Building" ReadOnly="True" SortExpression="BuildingNo" >
                <ItemStyle HorizontalAlign="Center" />
            </asp:BoundField>
            <asp:BoundField DataField="ActivityName" HeaderText="Activity" ReadOnly="True" SortExpression="ActivityName" >
                <ItemStyle HorizontalAlign="Center" />
            </asp:BoundField>
            <asp:BoundField DataField="Device" HeaderText="Device" ReadOnly="True" SortExpression="Device" visible="False" />
            <asp:BoundField DataField="ComputerName" HeaderText="ComputerName" ReadOnly="True"
                SortExpression="ComputerName" >
                <ItemStyle HorizontalAlign="Center" />
            </asp:BoundField>
            <asp:BoundField DataField="UserName" HeaderText="User" ReadOnly="True" SortExpression="UserName" />
            <asp:BoundField DataField="DateRequested" HeaderText="Date Requested" SortExpression="DateRequested" DataFormatString="{0:g}" ReadOnly="True" />
            <asp:CheckBoxField DataField="MACcomplete" HeaderText="Completed" SortExpression="MACcomplete" />
        </Columns>
        <SelectedRowStyle BackColor="#FFE0C0" ForeColor="#2A203B" Font-Bold="True" BorderColor="#2A203B" BorderStyle="Solid" BorderWidth="10px" Font-Size="Small" />
        <PagerStyle ForeColor="White" HorizontalAlign="Center" BorderColor="#2A203B" BorderStyle="Solid" BorderWidth="10px" />
        <HeaderStyle BackColor="#2A203B" Font-Bold="True" ForeColor="White" BorderColor="#2A203B" BorderStyle="Solid" BorderWidth="1px" HorizontalAlign="Center" />
        <AlternatingRowStyle BackColor="#EDEDED" ForeColor="#2A203B" BorderColor="#2A203B" BorderStyle="Solid" BorderWidth="10px" />
        <RowStyle BackColor="White" ForeColor="#2A203B" BorderColor="#2A203B" BorderStyle="Solid" BorderWidth="10px" />
        <EditRowStyle BorderStyle="Solid" BorderWidth="10px" HorizontalAlign="Center" Font-Bold="True" Font-Overline="False" Font-Size="Small" Font-Underline="True" />
        <EmptyDataRowStyle BorderColor="#2A203B" BorderStyle="Solid" BorderWidth="10px" HorizontalAlign="Center" />        
        <EmptyDataTemplate>
            <font color="red">No Open Work Orders</font>
        </EmptyDataTemplate>
    </asp:GridView>
    <asp:SqlDataSource ID="SqlDataSourceGrid" runat="server" ConnectionString="<%$ ConnectionStrings:SBRcs %>"
        SelectCommand="SELECT userid, BuildingNo, ActivityName, Device, ComputerName, SUBSTRING(UserName, 6, 20) AS UserName, MACcomplete, DateRequested FROM macreg WHERE (MACcomplete = @MACcomplete)" 
        UpdateCommand="UPDATE macreg SET MACcomplete = @MACcomplete ,DateCompleted = getdate() WHERE (userid = @userid )">
        <SelectParameters>
            <asp:Parameter DefaultValue="False" Name="MACcomplete" Type="Boolean" />
        </SelectParameters>
        <UpdateParameters>
            <asp:Parameter Name="MACcomplete" />
            <asp:Parameter Name="userid" />
        </UpdateParameters>
    </asp:SqlDataSource>
~~ Believe in Science, not religion.  Science will always progress, religions will always collapse. ~~

You can try this way.
fire a JavaScript function OnClick event of the checkBox.  (eg: OnClick = "test(this);")
and in that function u wil b able to write like this.
function test(obj)
{

document.getElementById('HiddenField').value = obj.parentElement.parentElement.children[3].children[1].children[0].innerText;
}
you can place a debugger and check for the exact value in trial and error method.
HTH
Muppidi.
~ Muppidi

If the DataKeys aren't being defined for whatever reason, Why not just add an attribute to the checkbox itself?
 <ItemTemplate> 
                  <asp:CheckBox ID="chkIsRequired" runat="server" Checked='<%# Eval("IsRequired") %>' MyKey='<%# Eval("IsRequired") %>AutoPostBack="true"  OnCheckedChanged="IsRequired_Click" />

    </ItemTemplate>
 
Then, in code, you could reference:
chk = e.FindControl("chkIsRequired")
 myVal =  chk.Attributes["MyKey"].ToString();
 
I've left out a lot of code, but hopefully it is clear what I am saying.

ecbruck i did define as u said but still i was not able to get the required id 
and thanks every one for sharing there code and try to help me but they are more complex for my knowledge i tried the ramireddyindia way and it did work .
Ahtesham