How to make this span not move my field?

Basically i have a form(within a table) and inside the form a field, the form is submitted via ajax, and i have a span which receives the output from the AJAX(when its received a response from the server).

The response is "Successfully updated" however as it turns out, the text actually moves my field. Is it possible for it not to do this?

<form method="GET" name="update_address">
<td align="left" class="rowhead">Address:</td>
<td align="left">
<input type="text" size="45" id="address" name="address" class="btcaddress" value="$value/>
<span style="display: inline-block;">
<input type="submit" name="submit" value="Update" size="45" onclick="javascript:xmlhttpPost('index.php?page=main&do=update_address', 'update_address', 'updated', ''); javascript:return false;"/>
</span><span id="updated">    </span>

Sorry for the improperly formatted code.

Use a DIV insted. It will on on its own line.