Having the page stored is what I do.
I created a little server application that serves a webpage and then outputs a submitted
string to an XBee attached to a USB port. The reply from the XBee is added to the webpage. The bulk of the page is stored. I programmatically add a few rows to a table.
The page I store is 250bytes (see the code below).
<html>
<head>
</head>
<body>
<h1>wiblocks XB2</h1>
<table>
<tr>
<td>
Send
<td>
<form method=GET action="write">
<input TYPE=text name=q size=20 maxlength=255 value="">
<input type=submit name=btnG bgcolor=cyan VALUE="SEND">
</table>
</body>
</html>