I use the following glut functions in borland c++ in a (form) Why the code gives the following error? [Linker Error] Unresolved external ''glutInitDisplayMode'' referenced from C:\DOCUMENTS AND SETTINGS\ÞEBNEM AKBULUT\DESKTOP\PRJV2.1\PRJV21.OBJ [Linker Error] Unresolved external ''glutCreateWindow'' referenced from C:\DOCUMENTS AND SETTINGS\ÞEBNEM AKBULUT\DESKTOP\PRJV2.1\PRJV21.OBJ [Linker Error] Unresolved external ''glutDisplayFunc'' referenced from C:\DOCUMENTS AND SETTINGS\ÞEBNEM AKBULUT\DESKTOP\PRJV2.1\PRJV21.OBJ The code is; void __fastcall TForm1::Button4Click(TObject *Sender) { MessageDlg("Display Object.", mtInformation, TMsgDlgButtons() << mbOK, 0); GLfloat rtri; GLfloat x_t,y_t,z_t; int n1,n2,n3; glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutCreateWindow("Your 3D Object"); glutDisplayFunc(RenderScene); SetupRC(); glTranslatef(0.0f,0.0f,-6.0f); glRotatef(rtri,1.0f,0.0f,0.0f); // Process each triangle .... Please help me..