XmNanchorUnderlineType
  Underlining style for anchors. Can be any of the following:

  XmNO_LINE | /* no underlines */
  XmSINGLE_LINE | /* a single, solid, underline */
  XmDOUBLE_LINE | /* a double, solid, underline */
  XmSINGLE_DASHED_LINE | /* a single, dashed, underline */
  XmDOUBLE_DASHED_LINE | /* a double, dashed, underline */

  This resource is only honored when the XmNanchorButtons resource is set to False