small asp.net

I have an admin login page that is throwing an error. There will be more work on this site -- adding on an ecommerce and other things but for now.... need someone who can fix this error. The client used to be able to manage photos on the site. Instead of the developer fixing his error in the admin - he removed all the pictures. We need this back so she can upload pics through the admin area. $10 (2 hours) to get this back up and running. Let me know if you think differently. Compiler Error Message: CS0012: The type '[login to view URL]' is defined in an assembly that is not referenced. You must add a reference to assembly '[login to view URL], Version=1.0.2547.27724, Culture=neutral, PublicKeyToken=null'.