function changeImage1(){
    document.kana.src="img/kanagawa_rank2.jpg";
}
function changeImage2(){
    document.kana.src="img/kanagawa_rank.jpg";
}
function changeImage3(){
    document.sina.src="img/sinagawa_rank2.jpg";
}
function changeImage4(){
    document.sina.src="img/sinagawa_rank.jpg";
}
function changeImage5(){
    document.kin.src="img/kinsi_rank2.jpg";
}
function changeImage6(){
    document.kin.src="img/kinsi_rank.jpg";
}
function changeImage7(){
    document.taji.src="img/tajiri_rank2.jpg";
}
function changeImage8(){
    document.taji.src="img/tajiri_rank.jpg";
}