if (document.images) {
  imageJPNon = new Image();
  imageJPNon.src ="/suzaku/.include/e/button/japanese_on.png";
  imageJPNoff = new Image();
  imageJPNoff.src ="/suzaku/.include/e/button/japanese_off.png";

  imageTOPon = new Image();
  imageTOPon.src ="/suzaku/.include/e/button/top_on.png";
  imageTOPoff = new Image();
  imageTOPoff.src ="/suzaku/.include/e/button/top_off.png";

  imageSUZAKUon = new Image();
  imageSUZAKUon.src ="/suzaku/.include/e/button/suzaku_on.png";
  imageSUZAKUoff = new Image();
  imageSUZAKUoff.src ="/suzaku/.include/e/button/suzaku_off.png";

  imageFLASHon = new Image();
  imageFLASHon.src ="/suzaku/.include/e/button/flash_on.png";
  imageFLASHoff = new Image();
  imageFLASHoff.src ="/suzaku/.include/e/button/flash_off.png";

  imageRESEARCHon = new Image();
  imageRESEARCHon.src ="/suzaku/.include/e/button/research_on.png";
  imageRESEARCHoff = new Image();
  imageRESEARCHoff.src ="/suzaku/.include/e/button/research_off.png";

  imageNEWSon = new Image();
  imageNEWSon.src ="/suzaku/.include/e/button/news_on.png";
  imageNEWSoff = new Image();
  imageNEWSoff.src ="/suzaku/.include/e/button/news_off.png";

  imageDOCon = new Image();
  imageDOCon.src ="/suzaku/.include/e/button/docs_on.png";
  imageDOCoff = new Image();
  imageDOCoff.src ="/suzaku/.include/e/button/docs_off.png";

  imageTDon = new Image();
  imageTDon.src ="/suzaku/.include/e/button/td_on.png";
  imageTDoff = new Image();
  imageTDoff.src ="/suzaku/.include/e/button/td_off.png";

  imagePRESENon = new Image();
  imagePRESENon.src ="/suzaku/.include/e/button/presentation_on.png";
  imagePRESENoff = new Image();
  imagePRESENoff.src ="/suzaku/.include/e/button/presentation_off.png";

  imagePROPon = new Image();
  imagePROPon.src ="/suzaku/.include/e/button/proposal_on.png";
  imagePROPoff = new Image();
  imagePROPoff.src ="/suzaku/.include/e/button/proposal_off.png";

  imageACCEPTon = new Image();
  imageACCEPTon.src ="/suzaku/.include/e/button/accept_on.png";
  imageACCEPToff = new Image();
  imageACCEPToff.src ="/suzaku/.include/e/button/accept_off.png";

  imageSCHEDon = new Image();
  imageSCHEDon.src ="/suzaku/.include/e/button/schedule_on.png";
  imageSCHEDoff = new Image();
  imageSCHEDoff.src ="/suzaku/.include/e/button/schedule_off.png";

  imagePLANon = new Image();
  imagePLANon.src ="/suzaku/.include/e/button/obsplan_on.png";
  imagePLANoff = new Image();
  imagePLANoff.src ="/suzaku/.include/e/button/obsplan_off.png";

  imageLOGon = new Image();
  imageLOGon.src ="/suzaku/.include/e/button/obslog_on.png";
  imageLOGoff = new Image();
  imageLOGoff.src ="/suzaku/.include/e/button/obslog_off.png";

  imagePROCon = new Image();
  imagePROCon.src ="/suzaku/.include/e/button/processing_on.png";
  imagePROCoff = new Image();
  imagePROCoff.src ="/suzaku/.include/e/button/processing_off.png";

  imageARCHIVEon = new Image();
  imageARCHIVEon.src ="/suzaku/.include/e/button/archive_on.png";
  imageARCHIVEoff = new Image();
  imageARCHIVEoff.src ="/suzaku/.include/e/button/archive_off.png";

  imageANAon = new Image();
  imageANAon.src ="/suzaku/.include/e/button/analysis_on.png";
  imageANAoff = new Image();
  imageANAoff.src ="/suzaku/.include/e/button/analysis_off.png";

  imageCALDBon = new Image();
  imageCALDBon.src ="/suzaku/.include/e/button/caldb_on.png";
  imageCALDBoff = new Image();
  imageCALDBoff.src ="/suzaku/.include/e/button/caldb_off.png";

  imagePUBon = new Image();
  imagePUBon.src ="/suzaku/.include/e/button/pub_on.png";
  imagePUBoff = new Image();
  imagePUBoff.src ="/suzaku/.include/e/button/pub_off.png";

  imageWAMon = new Image();
  imageWAMon.src ="/suzaku/.include/e/button/hxdwam_on.png";
  imageWAMoff = new Image();
  imageWAMoff.src ="/suzaku/.include/e/button/hxdwam_off.png";

  imageBIBon = new Image();
  imageBIBon.src ="/suzaku/.include/e/button/bib_on.png";
  imageBIBoff = new Image();
  imageBIBoff.src ="/suzaku/.include/e/button/bib_off.png";

  imageHELPon = new Image();
  imageHELPon.src ="/suzaku/.include/e/button/help_on.png";
  imageHELPoff = new Image();
  imageHELPoff.src ="/suzaku/.include/e/button/help_off.png";

  imageSWGon = new Image();
  imageSWGon.src ="/suzaku/.include/e/button/swg_on.png";
  imageSWGoff = new Image();
  imageSWGoff.src ="/suzaku/.include/e/button/swg_off.png";

}

function turnOn(imageName) {
  if (document.images) {
    document[imageName].src = eval(imageName + "on.src");
  }
}

function turnOff(imageName) {
  if (document.images) {
    document[imageName].src = eval(imageName + "off.src");
  }
}