//スモールイメージの数
var preimg1 = new Array(8);
for (i=1;i<8;i++){
    preimg1[i] = new Image;
    preimg1[i].src = "img/gal_simg_00"+(i)+"o.jpg";
}
//ダウンロード1024の数
var preimg3 = new Array(8);
for (i=1;i<8;i++){
    preimg3[i] = new Image;
    preimg3[i].src = "img/gal_size24_00"+(i)+"o.gif";
}

//ダウンロード1080の数
var preimg4 = new Array(8);
for (i=1;i<8;i++){
    preimg4[i] = new Image;
    preimg4[i].src = "img/gal_size80_00"+(i)+"o.gif";
}


function chimg1(over){
img1 = new Image;
img1.src = "img/gal_"+over+"o.jpg";
document.images[over].src = img1.src;
return true;
}

function bkimg1(out){
img2 = new Image;
img2.src = "img/gal_"+out+".jpg";
document.images[out].src = img2.src;
return true;
}

function chimg3(over){
img1 = new Image;
img1.src = "img/gal_"+over+"o.gif";
document.images[over].src = img1.src;
return true;
}

function bkimg3(out){
img2 = new Image;
img2.src = "img/gal_"+out+".gif";
document.images[out].src = img2.src;
return true;
}

function chimg4(over){
img1 = new Image;
img1.src = "img/gal_"+over+"o.gif";
document.images[over].src = img1.src;
return true;
}

function bkimg4(out){
img2 = new Image;
img2.src = "img/gal_"+out+".gif";
document.images[out].src = img2.src;
return true;
}