ファンクション
function ○○○ ( 引数){
処理・・・;
}
<body>
<script type="text/javascript">
function keisan(x, y){
return x+y;
}
document.write(keisan(500,300));
</script>
</body>

function ○○○ ( 引数){
処理・・・;
}
<body>
<script type="text/javascript">
function keisan(x, y){
return x+y;
}
document.write(keisan(500,300));
</script>
</body>
