<!DOCTYPE html>
<html lang="ru" xml:lang="ru" xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width" />
<title> input type javascript </title>
<script>
var aa=2;
switch (aa) {
case 1:
alert ('a=1');
break;
case 2:
alert ('a=2');
break;
case 3:
alert ('a=3');
break;
}
</script>
<body>
</body>
</html>