关于生成动态库的错误

我用VC6.0建了一个导出动态库的工程，具体是：New/Projects/Win32 Dyanmic-Link Library，然后选择了An Empty Dll Project，然后加入了我的程序代码文件及定义

导出符号def文件，其中def文件的内容如下：

; orasbt.def : Declares the module parameters for the DLL.
LIBRARY "orasbt"
DESCRIPTION 'orasbt Windows Dynamic Link Library'
EXPORTS
; Explicit exports can go here
sbtclose
sbtinfo
sbtinit
sbtopen
sbtread
sbtremove
sbtwrite

编译后产生错误：
--------------------Configuration: orasbt - Win32 Debug------------------

--
Linking...
orasbt.def : error LNK2001: unresolved external symbol sbtclose
orasbt.def : error LNK2001: unresolved external symbol sbtinfo
orasbt.def : error LNK2001: unresolved external symbol sbtinit
orasbt.def : error LNK2001: unresolved external symbol sbtopen
orasbt.def : error LNK2001: unresolved external symbol sbtread
orasbt.def : error LNK2001: unresolved external symbol sbtremove
orasbt.def : error LNK2001: unresolved external symbol sbtwrite
Debug/orasbt.lib : fatal error LNK1120: 7 unresolved externals
LINK : fatal error LNK1141: failure during build of exports file
Error executing link.exe.

orasbt.dll - 9 error(s), 0 warning(s)

程序没有错误，只是代码文件多一些。现在编译老是出这个问题，请问哪位大哥大姐小弟小妹知道解决？先谢了