XSetWindowBorderWidth(display, w, width)
      Display *display;
      Window w;
      unsigned int width;
| display | Specifies the connection to the X server. | 
| w | Specifies the window. | 
| width | Specifies the width of the window border. | 
XSetWindowBorderWidth() can generate a BadWindow error.
| BadWindow | A value for a Window argument does not name a defined Window. |