error LNK2019: unresolved external symbol

[WiddleSticks]

I know my SDL is set to all the right directories. I don't know what is causing this. I also have all my dll files in the debug folder. It has worked before, I just don't know why it isn't working now. Any help would be greatly appreciated. Here is my error message:

gui.obj : error LNK2019: unresolved external symbol _TTF_Init referenced in function "private: void __thiscall GUI::initGUI(void)" (?initGUI@GUI@@AAEXXZ)

gui.obj : error LNK2019: unresolved external symbol _TTF_OpenFont referenced in function "private: void __thiscall GUI::initGUI(void)" (?initGUI@GUI@@AAEXXZ)

gui.obj : error LNK2019: unresolved external symbol _TTF_RenderText_Solid referenced in function "public: void __thiscall GUI::displayGameState(int,int,int,int,int,int,int,float *,float *,int *)" (?displayGameState@GUI@@QAEXHHHHHHHPAM0PAH@Z)

hmwk.2.obj : error LNK2019: unresolved external symbol "void __cdecl changeGameState(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,float &,float &,int &,float &,float &,int &,int,float * const,float * const,int * const)" (?changeGameState@@YAXV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@AAM1AAH112HQAM3QAH@Z) referenced in function _SDL_main