/*
   New Perspectives on JavaScript
   Tutorial 1
   Tutorial Case


   Function List:
   stringReverse
      Used to reverse the order of characters in a text string

*/


function stringReverse(textString) {
   if (!textString) return '';
   var revString='';
   for (i = textString.length-1; i>=0; i--)
       revString+=textString.charAt(i)
   return revString;
}

function showEM(userName,emServer) {

/*
   The showEM() function displays a link to the user's e-mail address.  The username and e-mail server name are entered in reverse order to thwart e-mail harvesting programs.
*/

   userName = stringReverse(userName); // undo the reversed username
   emServer = stringReverse(emServer); // undo the reversed server name
   var emLink = userName + "@" + emServer; // combine the username and server name
   document.write("<a href='mailto:"+emLink+"'>");
   document.write(emLink);
   document.write("</a>");
}