Problem opening application from Web Server

[MrMike]

I'm building my first asp.net application, and I've successfully copied it to
my webserver using CopyProject. However, now when I attempt to open the
application on the server I get the error message
--------------------------------------------------------------------------------------
Configuration Error
Description: An error occurred during the processing of a configuration file
required to service this request. Please review the specific error details
below and modify your configuration file appropriately.

Parser Error Message: File or assembly name
CrystalDecisions.CrystalReports.Engine, or one of its dependencies, was not
found.

Source Error:
Line 16: debugging ASP.NET files.
Line 17: -->
Line 18: <compilation defaultLanguage="vb" debug="true"><assemblies><add
assembly="CrystalDecisions.CrystalReports.Engine, Version=9.1.5000.0,
Culture=neutral, PublicKeyToken=692fbea5521e1304"/><add
assembly="CrystalDecisions.ReportSource, Version=9.1.5000.0, Culture=neutral,
PublicKeyToken=692fbea5521e1304"/><add assembly="CrystalDecisions.Shared,
Version=9.1.5000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/><add
assembly="CrystalDecisions.Web, Version=9.1.5000.0, Culture=neutral,
PublicKeyToken=692fbea5521e1304"/></assemblies></compilation>
Line 19:
Line 20: <!-- CUSTOM ERROR MESSAGES

--------------------------------------------------------------------------------------

Could someone please let me know what to do to fix this? Thanks.