I need help, how I use this function to display image in matlab gui separately by double clicking ?

if true
  % code
end
function openSpecificImage(handles)
  type = get(gcf,'SelectionType');
  switch type
      case 'open' % double-click
          im = get( gcbo,'cdata' );
          imtool(im, [min(im(:)) max(im(:))] )
          case 'normal'   
          %left mouse button action
      case 'extend'
          % shift & left mouse button action
      case 'alt'
          % alt & left mouse button action
end