if (document.images) {
   img1 = new Image(); img1.src = "../img/texikki_button2.gif";
   img2 = new Image(); img2.src = "../img/kadexie_button2.gif";
   img3 = new Image(); img3.src = "../img/dexyuaru_a_2.gif";
   img4 = new Image(); img4.src = "../img/dexyuaru_b_2.gif";
}
function setImage(img, image) {
   if (img) {
      img.src = image;
   }
}
/*各種ボタン設定*/
function texikki_on(){
setImage(document.img1, 'img/texikki_button2.gif')
}
function texikki_out(){
setImage(document.img1, 'img/texikki_button1.gif')
}
function kadexie_on(){
setImage(document.img2, 'img/kadexie_button2.gif')
}
function kadexie_out(){
setImage(document.img2, 'img/kadexie_button1.gif')
}
function dexyuaru_a_on(){
setImage(document.img3, 'img/dexyuaru_a_2.gif')
}
function dexyuaru_a_out(){
setImage(document.img3, 'img/dexyuaru_a_1.gif')
}
function dexyuaru_b_on(){
setImage(document.img4, 'img/dexyuaru_b_2.gif')
}
function dexyuaru_b_out(){
setImage(document.img4, 'img/dexyuaru_b_1.gif')
}