这错了吗，感觉没错呀！
不能等于5，等于5长度就是6了
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>二维数组</title>
<script type="text/javascript">
var myarr = new Array();
for(var i = 0 ; i<3;i++){
myarr[i]=new Array();
for(var j=0;j<5;j++){
myarr[i][j]=i*j;
document.write(myarr[i][j]);
}
document.write("<br>");
}
</script>
</head>
<body>
</body>
</html>