var imgMax = 7;    // imgRandom の最大値＋1
  var imgRandom = Math.floor(Math.random() * imgMax);
  var tag1 = "<style type='text/css' media='screen, projection, tv, print'>";
  var tag2 = "div.menu h2#rss { background-image: url(./image/Feed-";
  var tag3 = ".png)\; }";
  var tag4 = "</style>";
     if(imgRandom == 0)  document.write(tag1 + tag2 + "Gray" + tag3 + tag4);
else if(imgRandom == 1)  document.write(tag1 + tag2 + "Green" + tag3 + tag4);
else if(imgRandom == 2)  document.write(tag1 + tag2 + "LGreen" + tag3 + tag4);
else if(imgRandom == 3)  document.write(tag1 + tag2 + "Orange" + tag3 + tag4);
else if(imgRandom == 4)  document.write(tag1 + tag2 + "Pink" + tag3 + tag4);
else if(imgRandom == 5)  document.write(tag1 + tag2 + "Purple" + tag3 + tag4);
else if(imgRandom == 6)  document.write(tag1 + tag2 + "Red" + tag3 + tag4);
else if(imgRandom == 7)  document.write(tag1 + tag2 + "BlueR" + tag3 + tag4);
else if(imgRandom == 8)  document.write(tag1 + tag2 + "GreenR" + tag3 + tag4);
else if(imgRandom == 9)  document.write(tag1 + tag2 + "OrangeR" + tag3 + tag4);
else if(imgRandom == 10)  document.write(tag1 + tag2 + "PurpleR" + tag3 + tag4);
else if(imgRandom == 11)  document.write(tag1 + tag2 + "RedR" + tag3 + tag4);
else if(imgRandom == 12)  document.write(tag1 + tag2 + "YellowR" + tag3 + tag4);