100以内偶数求和（循环练习）
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script>
var s=0;
for(var a=1;a<=10;a++)
{
if(a%2!=0)
{
continue;
}
s=s+a;
}
document.write(s);
</script>
</body>
</html>
