class instance error (multiple)

[david Binney]

when i try to compile a simple class i get the message
that there are multiple instances of the class which is
as follows:

Compiler Error Message:
CS1595: 'Temperature.TemperatureCB' is defined in
multiple places; using definition
from 'C:\WINDOWS\Microsoft.NET\Framework\v1.0.3705
\Temporary ASP.NET Files\mcsd\63097906\8e1380c7
\assembly\dl2\6ae8ccf6\144c738b_f9afc301\MCSD.DLL'


does anyone have any ideas on how to fix this error.