function HpbImgPreload()
{
  var appVer=parseInt(navigator.appVersion);
  var isNC=false,isN6=false,isIE=false;
  if (document.all && appVer >= 4) isIE=true; else
    if (document.getElementById && appVer > 4) isN6=true; else
      if (document.layers && appVer >= 4) isNC=true;
  if (isNC||isN6||isIE)
  {
    if (document.images)
    {
      var imgName = HpbImgPreload.arguments[0];
      var cnt;
      swImg[imgName] = new Array;
      for (cnt = 1; cnt < HpbImgPreload.arguments.length; cnt++)
      {
        swImg[imgName][HpbImgPreload.arguments[cnt]] = new Image();
        swImg[imgName][HpbImgPreload.arguments[cnt]].src = HpbImgPreload.arguments[cnt];
      }
    }
  }
}

<!--HPB_SCRIPT_PLD_50
HpbImgPreload('_HPB_ROLLOVER1', 'buttons/home/1.gif', 'buttons/home/2.gif');
HpbImgPreload('_HPB_ROLLOVER2', 'buttons/company/1.gif', 'buttons/company/2.gif');
HpbImgPreload('_HPB_ROLLOVER3', 'buttons/contents/1.gif', 'buttons/contents/2.gif');
HpbImgPreload('_HPB_ROLLOVER4', 'buttons/work/1.gif', 'buttons/work/2.gif');
HpbImgPreload('_HPB_ROLLOVER5', 'buttons/contact/1.gif', 'buttons/contact/2.gif');
HpbImgPreload('_HPB_ROLLOVER6', 'buttons/recruit/1.gif', 'buttons/recruit/2.gif');
HpbImgPreload('_HPB_ROLLOVER7', 'buttons/blog/1.gif', 'buttons/blog/2.gif');
HpbImgPreload('_HPB_ROLLOVER8', 'buttons/link/1.gif', 'buttons/link/2.gif');
//-->