VDisplayScale - displays a multi-resolution scale in the dialog window.
  float value;
  char *label;
  VDisplayScale displays a multi-resolution scale in the dialog window.
VDisplayScale checks if the dialog window is in front of the image window; if
it is, VDisplayScale displays the scale at the lowest resolution (default)
with the specified related values like min, max, width, and the x, y location.
This value is set by calling VSetScaleInformation. If the dialog window is not
in front of the image window, VDisplayScale stores the scale in a pixmap.
Return Value
  0 - work successfully.
  1 - memory allocation error.
  217 - cannot display the scale when panel is on in the panel area.
  243 - scale is out of the dialog window boundary.
  244 - scale does not exist.
  246 - scale width is greater than the available width of the dialog window.
  247 - scale width  is too small to satisfy the minimum requirement.
  249 - scale is already on.
  258 - pixmap is NULL and image window is in front of the dialog window.
  value - the default value to be shown on the scale; it must be between the
	min and max values of the scale.
  label - the name of the multi-resolution scale.
Side Effects
Entry Conditions
  VSetScaleInformation should be called first. If value is out of range or 
label is NULL or VCreateColormap not called earlier, VDisplayScale prints an 
error message to the standard error stream, produces a core dump file and 
exits from the current process.
Related Functions
VSelectScaleValue, VEraseScale, VGetScaleInformation, VSetScaleInformation, VGetScaleLayoutInformation, VCheckScaleEvents.