Searching Strings - Chapter 12-1

<html xmlns = "http://www.w3.org/1999/xhtml">
   <head>
      <title>
         Searching Strings with indexOf and lastIndexOf
      </title>

      <script type = "text/javascript">
         <!--
         var letters = "abcdefghijklmnopqrstuvwxyzabcdefghijklm";

         function buttonPressed()
         {
            searchForm.first.value =
               letters.indexOf( searchForm.inputVal.value );
            searchForm.last.value =
               letters.lastIndexOf( searchForm.inputVal.value );
            searchForm.first12.value =
               letters.indexOf( searchForm.inputVal.value, 12 );
            searchForm.last12.value =
               letters.lastIndexOf(
                  searchForm.inputVal.value, 12 );
         }
         // -->
      </script>

   </head>
   <body>
      <form name = "searchForm" action = "">
         <h1>The string to search is:<br />
             abcdefghijklmnopqrstuvwxyzabcdefghijklm</h1>
         <p>Enter substring to search for
         <input name = "inputVal" type = "text" />
         <input name = "search" type = "button" value = "Search"
                onclick = "buttonPressed()" /><br /></p>

         <p>First occurrence located at index
         <input name = "first" type = "text" size = "5" />
         <br />Last occurrence located at index
         <input name = "last" type = "text" size = "5" />
         <br />First occurrence from index 12 located at index
         <input name = "first12" type = "text" size = "5" />
         <br />Last occurrence from index 12 located at index
         <input name = "last12" type = "text" size = "5" /></p>
      </form>
   </body>
</html>