declaring link button value globally

public void view_onclick(object sender, EventArgs e)

{

int id = Convert.ToInt32((sender as LinkButton).CommandArgument);

SqlDataAdapter ad = new SqlDataAdapter("viewmasterid", con);

ad.SelectCommand.CommandType = CommandType.StoredProcedure;

ad.SelectCommand.Parameters.AddWithValue("@id", id);

DataTable dt = new DataTable();

ad.Fill(dt);

con.Close();

HiddenField1.Value = id.ToString();

txtname.Text = dt.Rows[0]["Name"].ToString();

txtage.Text = dt.Rows[0]["Age"].ToString();

}

how can i use this id value globally in my project?