How to use switch – case in java Script

<script language="javascript">

var x='s';

switch(x)

{

      case 'a':

      document.write("<h1>x=a</h1>");

      break;

      case 'b':

      document.write("<h1>x=b</h1>");

      break;

      case 's':

      document.write("<h1>x=s</h1>");

      break;

      case 'k':

      document.write("<h1>x=k</h1>");

      break;

 default:

      document.write("no default case.");

     

}

</script> //remove the break and check what happened