function ranImg(){
ran = Math.floor(Math.random() * 3);        //6までの乱数を発生させ結果の最も小さい整数をranに代入
    if(ran == 0){
        document.write('<img src="images/index.jpg" width="700" height="435" border="0">');
    } else if(ran == 1){
        document.write('<img src="images/index01.jpg" width="700" height="435" border="0">');
    } else if(ran == 2){
        document.write('<img src="images/index02.jpg" width="700" height="435" border="0">');
    }

}
function ranImg2(){
ran2 = Math.floor(Math.random() * 3);        //6までの乱数を発生させ結果の最も小さい整数をranに代入
    if(ran2 == 0){
        document.write('<img src="images/top03.jpg" width="750" height="435" border="0">');
    } else if(ran2 == 1){
        document.write('<img src="images/top02.jpg" width="750" height="435" border="0">');
    } else if(ran2 == 2){
        document.write('<img src="images/top01.jpg" width="750" height="435" border="0">');
    }

}