//Connection class

using System.Data.OleDb;

public class Class1
{
    public void connect(OleDbConnection con)
    {
      string str =   "provider=sqloledb;database=sample;uid=sa;pwd=xxx;";
      if(con.State == ConnectionState.Closed)
      {
         con.ConnectionString = str;
         con.Open();
      }
    }
}

public partial class _Default : System.Web.UI.Page 
{
    Class1 obj = new Class1();
}  

private void rptrJobfairbind()
    {
        string sql = "select JobfairName from JobfairPostings";
        OleDbConnection con = new OleDbConnection();
        obj.connect(con);
        OleDbDataAdapter da = new OleDbDataAdapter(sql, con);
        DataSet ds = new DataSet();
        da.Fill(ds);
        
        rptrJfaircategory.DataSource = ds;
        rptrJfaircategory.DataBind();
   }