symbol referencing errors by linking

Hello,

 

I have an error when I build my project. I use ccstudio 3.1

I am using the Simulink coder to generate code for my program ( to convert the Simulink module into C).

the error is:

<Linking>

undefined                        first referenced
 symbol                              in file
---------                        ----------------
_rt_MatMultRR_Dbl                C:\Programme\MATLAB\R2006b\work\g_t_ert_rtw\Debug\g_t.obj
>>   error: symbol referencing errors - './Debug/g_t_main.out' not built

>> Compilation failure

Build Complete,
  2 Errors, 1 Warnings, 0 Remarks.

the function performes matrix mulitplication and its library is included in the project. But I don't know where is the mistake.

i appreciate your help