<script>
   with(document)
   {
      //返回exp函數(shù)的幾個算例
      write(e(-2));
      write(e(0));
      write(e(2));
   }
   //自定義函數(shù)返回exp函數(shù)值
   function e(x)
   {
      var xstr=new String(x);
      var rstr= "e"+xstr.sup()+"="+Math.exp(x);
      return rstr+"<br>";
   }
</script>