getString for MComboBoxPeer

struct Hjava_lang_String * 
sun_awt_motif_MComboBoxPeer_getString(
      struct Hsun_awt_motif_MComboBoxPeer *this)
{
   struct ComponentData *cdata = PDATA(ComponentData, this);
   char *str;

   if (cdata == 0 || cdata->widget == 0) {
      SignalError(0, JAVAPKG "NullPointerException", 0);
      return 0;
   }
   AWT_LOCK();
   str = XmComboBoxValue(cdata->widget);
   AWT_UNLOCK();
   return makeJavaString(str, strlen(str));
}