Could not find any resources appropriate for the specified culture or the neutral culture.

Hi everyone,
               in my project i m creating one class library and in that Class library i have one resources file in which all the runtime message are written.
i m using that class library's dll file in my website. and when i m running my website at runtime it gives this Error that.
"Could not find any resources appropriate for the specified culture or the neutral culture.  Make sure "Lib.UserMessages.resources" was correctly embedded or linked into assembly "Lib" at compile time, or that all the satellite assemblies required are loadable and fully signed."
              When application goes to get message from the resource file it will throw error...i don't konw how to handle this error.. Plz Help me..... 
             Thanxs in Adv.............




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