unable to call or view the functions in file.dll in matlab?

I tried to call a function from a shared library and I get the following error

calllib('EnobioAPI','openDevice') ??? Error using ==> calllib Method was not found.

when I tried to view the function I got this error

libfunctionsview EnobioAPI ??? Error using ==> methodsview at 103 No library lib.EnobioAPI can be located or no methods for library

Error in ==> libfunctionsview at 39 methodsview(qcls, 'libfunctionsview');

[Nada]

please help

[Geoff]

Did you call loadlibrary first?

[Nada]

Yes

[Nada]

I tried to call some of enobio functions from the matlab using the following code:

loadlibrary EnobioAPI.dll Enobio.h...

addheader EnobioAPI_global...

addheader EnobioData...

addheader IDataConsumer...

addheader IDataProcessor ...

addheader IDataProducer...

addheader PData...

addheader Property...

addheader StatusData

calllib('EnobioAPI','openDevice')

but I get the following error:

Warning: The library class 'EnobioAPI' already exists. Use a classname alias.

> In loadlibrary at 179

In try1 at 1

??? Error using ==> calllib

Method was not found.

Error in ==> try1 at 10

calllib('EnobioAPI','openDevice')

[Philip Borghesani]

Warning: The library class 'EnobioAPI' already exists. Use a classname alias.

When you get this warning your library was not (re)loaded. Use unloadlibrary first before trying to load the library with new options.

[Nada]

what abaout :

??? Error using ==> calllib

Method was not found.

Error in ==> try1 at 10

calllib('EnobioAPI','openDevice')