document.write("<style type=\"text/css\">a.sample span {visibility : hidden ;} a.sample:hover span {visibility : visible ;} img.visible {visibility : hidden ;} a:hover img.visible {visibility : visible ;} a.sample:link {padding:0; border: 0 none; text-decoration : none ; color:black;} a.sample:visited{padding:0; border: 0 none; text-decoration : none ; color:black;} a.sample:active{padding:0; border: 0 none; color:black; text-decoration : none ; background:transparent;} a.sample:hover{padding:0; border: 0 none; color:black; text-decoration : none ; background:transparent;}</style>");
document.write("<p>何が現れるかな！下（↓）の空白領域にカーソルをのせてみよう<br />");
document.write("<a href=\"../../sample/css/visibility.jpg\" class=\"sample\"><img src=\"../../sample/css/visibility.jpg\" class=\"visible\" width=\"323\" heihgt=\"299\" alt=\"コアラ\" />");
document.write("<br /><span style=\"color:black;\">ジャジャーン！「コアラ」さんでした！</span></a></p>");