   glext problem
  i find some old problem can not complied now ,but it  could complied before.the vc said this has error:    PFNGLACTIVETEXTUREARBPROC    glActiveTextureARB= NULL;the error is: gl_app.cpp(26) : error C2146: syntax error : missing ';' before identifier 'glActiveTextureARB'   gl_app.cpp(26) : error C2501: 'PFNGLACTIVETEXTUREARBPROC' : missing storage-class or type specifiers   gl_app.cpp(26) : fatal error C1004: unexpected end of file foundwhy? this code worked very well before.   
  You have probably changed your gl headers and PFNGLACTIVETEXTUREARBPROC is no longer declared in them..   ;  i update the glext.h  but this application uses the old version glext.h which is under the app's dir.