function rand_number(n)
{
var x;
x=Math.round(Math.random()*100);
x%=n;
return x;
}
function music()
{
var son = new Array();
son[0]='<embed src=4.mid hidden=true autostart=true>';
son[1]='<embed src=5.mid hidden=true autostart=true>';
var n=rand_number(2); 
document.write(son[n]);
}