title: GTK_IS_WIDGET(WIDGET) failed
body: <p>I am currently trying to learn how to use GTK with C on a Windows 7 computer. I suppose that is my first problem I'm running in to.</p>
  
  <p>I am following a tutorial series located here: <a href="http://www.micahcarrick.com/gtk-glade-tutorial-part-1.html#Manipulating_Widget_Properties" rel="nofollow">http://www.micahcarrick.com/gtk-glade-tutorial-part-1.html#Manipulating_Widget_Properties</a></p>
  
  <p>Following all of the steps, I get to the point where I compile. The program compiles fine and when I run it, I get the GTK_IS_WIDGET(WIDGET) error. Upon investigation of this function, it seems to be that the most common error is a mismatch between the name of your topmost window in the Glade design, and the call in the function. I renamed both the window and call to just normal "window" and I get the same error.</p>
  
  <p>Upon debugging the code, </p>
  
  <pre><code>gtk_builder_add_from_file (builder, "tutorial.xml", NULL);
  window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
  </code></pre>
  
  <p>This line appears to be what I believe to be the line in question. window gets set to null after this line and I'm assuming that is where the issue comes from. </p>
  
  <p>Double checking everything, my top most window is still named "window" and the tutorial file is spelled correctly and called "tutorial.glade"</p>
  
  <p>Any help is appreciated.
  Thank you.</p>