title: Define glDebugMessageCallbackARB callback method
body: <p>Im using glew to use openGL extensions. I am trying to use <em>GL_ARB_debug_output</em> extension.</p>
  
  <p>I added the flag WGL_CONTEXT_DEBUG_BIT_ARB while context creation, so context created with debug support.</p>
  
  <p>While trying to define callback method for <em>glDebugMessageCallbackARB</em> i found the following function from a blog</p>
  
  <pre><code>void CALLBACK DebugCallback(unsigned int source, unsigned int type,
                              unsigned int id, unsigned int severity,
                              int length, const char* message, void* userParam);
  </code></pre>
  
  <p>but when add the line</p>
  
  <pre><code>glDebugMessageCallbackARB(&amp;DebugCallback, NULL);
  </code></pre>
  
  <p>the following error is generated </p>
  
  <pre><code>cannot convert parameter 1 from 'void (__stdcall *)(unsigned int,unsigned int,unsigned int,unsigned int,int,const char *,void *)' to 'GLDEBUGPROCARB'
  </code></pre>
  
  <p>Can any one help me to understand this error so that i can resolve.</p>