function flag(){
var flag;
flag=false;
}

function imginit(){
altimg=new Array;
altimg[0]=Image(570,200);
altimg[0].src="housekisozai/saisyo.jpg";
altimg[1]=Image(570,200);
altimg[1].src="housekisozai/datebase.jpg";
altimg[2]=Image(570,200);
altimg[2].src="housekisozai/iroiro.jpg";
flag=true;
}

function alternate(ID,numx){
if(flag==true){
if(ID=="alti"){
document.getElementById(ID).
src=altimg[numx].src;
}
}
return;
}