ExecuteReader Error

Can anyone tell me what is wrong with this code :

SqlConnection con = new SqlConnection("Data Source=(local);Initial Catalog=Orders; User id=sa");
   
SqlCommand comm = new SqlCommand("Select * from cust", con);
con.Open();
SqlDataReader dr = comm.ExecuteReader();
while (dr.Read())
{
      Response.Write(dr.GetSqlValue(0).ToString());
      Response.Write(dr.GetSqlValue(1).ToString());
}

Whenever i try to execute this code, it displays the following error:

Server Error in '/Orders' Application.

Unknown error.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Unknown error.

Source Error:

Line 44:    
Line 45:             SqlCommand comm = new SqlCommand("Select * from cust", con);
Line 46:    con.Open();
Line 47:    SqlDataReader dr = comm.ExecuteReader();
Line 48:   
 

Source File: c:\inetpub\wwwroot\orders\customerdetailsform.aspx.cs    Line: 46

Stack Trace:

[SqlException: Unknown error.]
   System.Data.SqlClient.ConnectionPool.GetConnection(Boolean& isInTransaction)
   System.Data.SqlClient.SqlConnectionPoolManager.GetPooledConnection(SqlConnectionString options, Boolean& isInTransaction)
   System.Data.SqlClient.SqlConnection.Open()
   Orders.CustomerDetailsForm.Page_Load(Object sender, EventArgs e) in c:\inetpub\wwwroot\orders\customerdetailsform.aspx.cs:46
   System.Web.UI.Control.OnLoad(EventArgs e)
   System.Web.UI.Control.LoadRecursive()
   System.Web.UI.Page.ProcessRequestMain()

Can anyone give me a solution for this.

Thanks,

Shailaja.