PROTO slideset [
      exposedField SFInt32    visible 0
      exposedField MFNode     slides []
      eventIn SFInt32         next
  ] {
      DEF select Switch {
          choice      IS slides
          whichChoice IS visible
      }
  
      Script {
      directOutput TRUE
      eventIn SFInt32 next IS next
      field SFInt32 slide IS visible
      field SFNode select USE select
      field MFNode slides []
      url "javascript:
      function next(value) {
      slides = select.choice;
      Browser.print('=' + slide + ' ' + slides.length);
      if (slide >= (slides.length-1)) slide = 0;
      else slide += 1;
      select.whichChoice = slide;
      }"
      } ## end script
  }