[Mono-list] Help - what's wrong?

[Kiyeon]

Hi, all
I'm trying to use pgsql with xsp.
Here is a error message.

=============================================================
Server Error in '/' Application

________________________________________________________________________
Compilation Error
Description: Error compiling a resource required to service this
request. Review your source file and modify it to fix this error. 

Error message: /home/yeon/www/write.cs(6,0) : error CS0246: The
namespace `Mono.Data.PostgreSqlClient' can not be found (missing
assembly reference?) (0,0) : error failed: 1 error(s), 0 warnings

File name:  /home/yeon/www/write.cs

Line 1: namespace Board {
Line 2: 
Line 3: using System;
Line 4: using System.Collections;
Line 5: using System.Data;
Line 6: using Mono.Data.PostgreSqlClient;Line 7: using System.Web;
Line 8: using System.Web.UI;
Line 9: 
Line 10: public class Write : System.Web.UI.Page {
Line 11: 
Line 12: 	private string connectionString = 
Line 13: 		"Server=localhost;" +
Line 14: 		"Database=board;" +
Line 15: 		"User ID=yeon;" +
Line 16: 		"Password=a";
Line 17: 
Line 18: 	private void Page_Load (object sender, System.EventArgs e)
Line 19: 	{
Line 20: 		IDbConnection dbcon;
Line 21: 		dbcon = new PgConnecton (connectionString);
Line 22: 		dbcon.Open ();
Line 23: 		dbcon.Close ();
Line 24: 		dbcon = null;
Line 25: 	}
Line 26: }
Line 27: 
Line 28: } //namespace
==========================================================

But 'Mono.Data.PostgreSqlClient.dll' is in /usr/lib.
What's wrong? help please..