Callback

i am calling function in my code as

iaxc_set_event_callback(handle_iaxc_callback);

but getting an error

'iaxc_set_event_callback' : cannot convert parameter 1 from 'int (struct iaxc_event_struct)' to 'int (__stdcall *)(struct iaxc_event_struct)'
    ;    None of the functions with this name in scope match the target type

and I define function as

int  handle_iaxc_callback (iaxc_event e)

{

}

Please help me in this regard how shud i call this function and define it?