function optOnIconMouseDownListener (e) { // outlineIcons.src.icon_opton  needed?
    var target = thisOutline.targetOf(e)
    var p = target.parentNode
    termWidget.replaceIcon(p.parentNode,
      outlineIcons.termWidgets.optOn,
      outlineIcons.termWidgets.optOff, optOffIconMouseDownListener)
    p.parentNode.parentNode.removeAttribute('optional')
  }
function optOnIconMouseDownListener (e) { 
    var target = thisOutline.targetOf(e)
    var p = target.parentNode
    termWidget.replaceIcon(p.parentNode,
      outlineIcons.termWidgets.optOn,
      outlineIcons.termWidgets.optOff, optOffIconMouseDownListener)
    p.parentNode.parentNode.removeAttribute('optional')
  }
function optOnIconMouseDownListener ( e ) { // outlineIcons.src.icon_opton  needed? var target = thisOutline . targetOf ( e ) var p = target . parentNode termWidget . replaceIcon ( p . parentNode , outlineIcons . termWidgets . optOn , outlineIcons . termWidgets . optOff , optOffIconMouseDownListener ) p . parentNode . parentNode . removeAttribute ( 'optional' ) }
These woulkd be simpler using closer variables below
These woulkd be simpler using closer variables below