Timeout expired. The timeout period elapsed prior to completion of the operation of the server is not responding.

private DataSet Account_Statement_Schemewise(string ID, string Type, string FromDate, string ToDate)
    {
        System.Collections.Specialized.NameValueCollection nv = new System.Collections.Specialized.NameValueCollection();

        nv.Add("@Id", ID);
        nv.Add("@Type", Type);
        nv.Add("@FromDate", FromDate);
        nv.Add("@ToDate", ToDate);
        DataLayer Obj = new DataLayer
        return Obj .GetDataSet("statement", nv);
    }





 public DataSet GetDataSet(string Stored_Procedure, NameValueCollection nv)
    {
        DataSet ds = new DataSet();
        SqlConnection cn = new SqlConnection(objDBHelper.GetConnectionString());
        SqlCommand cmd = new SqlCommand(Stored_Procedure, cn);

        for (int i = 0; i < nv.Count; i++)
        {
            SqlParameter param;
            if (nv.Get(nv.AllKeys[i]) == null)
                param = new SqlParameter(nv.AllKeys[i], DBNull.Value);
            else
                param = new SqlParameter(nv.AllKeys[i], nv.Get(nv.AllKeys[i]));
            cmd.Parameters.Add(param);
        }
        cmd.CommandTimeout = 999999;
        cmd.CommandType = CommandType.StoredProcedure;
        SqlDataAdapter da = new SqlDataAdapter(cmd);

        try
        {
            cn.Open();
            da.Fill(ds);
        }
        catch (Exception ex)
        {

            da.Dispose();
            cmd.Connection.Close();
            cn.Close();
            throw ex;
        }
        finally
        {
            da.Dispose();
            cmd.Connection.Close();
            cn.Close();
        }
        return ds;
    }