>At learning Stage I have a problem in following code;
>
>SqlDataSource2.FilterExpression = "fld1 = " + TextBox1.Text; is giving column not error
>
>

>public partial class OffPage : System.Web.UI.Page
>{
>    SqlConnection con3 = new SqlConnection(ConfigurationManager.ConnectionStrings["LoginCS"].ConnectionString);
>    SqlCommand cmd3 = new SqlCommand();
>
>    protected void Page_Load(object sender, EventArgs e)
>    {
>       con3.Open();
>    }
>    protected void Button1_Click(object sender, EventArgs e)
>    {
>        if (Convert.ToInt32(RadioButtonList1.SelectedValue) == 0)
>        {
>            TextBox1.Text = "Pending";
>            SqlDataSource2.FilterExpression = "fld1 = " + TextBox1.Text;
>        }
>        if (Convert.ToInt32(RadioButtonList1.SelectedValue) == 1)
>        {
>            TextBox1.Text = "FWD";
>            SqlDataSource2.FilterExpression = "fld1 = " + TextBox1.Text;
>        }
>        
>    }
> }
>

Your problem is in not using the parameters. I also don't understand why do you mix SqlDataSource and SqlCommand. If you're using SqlCommand, look into SqlParameter, declare parameters for each of your expressions.