gridview is not binding on selected index change event of ddl

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C#

ASP.NET

hi,
i am trying to bind gridview on DDL SelectedIndexChanged event.
but grid is not bind.
query is perfect working in sql server.No compilation error.
i am using three layer code.

code is as follow.
.cs file--

protected void ddlRange_SelectedIndexChanged(object sender, EventArgs e)
    {

        BindGrid(ddlRange.SelectedValue.ToString());
            


    }

protected void BindGrid(string Language)
   {
       try
       {

           GridView1.DataSource = objMain.Selectinfo(Convert.ToInt32(Session["RANGE_ID"].ToString()));
           GridView1.DataBind();

       }
       catch (Exception ex)
       {
       }
       finally
       {


       }

   }

class file code--

public DataTable Selectinfo(int RANGE_ID)
        {
            ArrayList lstParam = new System.Collections.ArrayList();
            SqlParameter param;
            param = new SqlParameter();
            param.ParameterName = "@RANGE_ID";
            param.SqlDbType = SqlDbType.Int;
            param.Value = RANGE_ID;
            lstParam.Add(param);

            return (new ConnectivityStatusDAL.SQLDAL().SelectData("SP_SelectIinfo", lstParam, false));
        }

whats going wrong please help.
thanks