How do I show multiple iframes on a single page

Question

Hi
I have a web page with 2 iframes on it which point to 2 different webpages. I load the src url's on click of a button. It works fine on my development machine but when I deploy to a server and access the website from another machine, only 1 of the iframes gets refreshed. Can anyone help?
My code behind :
string vaUrl = obServ.VA_URL(pin);
string nrUrl = obServ.Characteristics_URL(pin);
iframe1.Attributes.Add("src", vaUrl);

iframe2.Attributes.Add("src", nrUrl);
 
And my html looks like this:
<table id="tblData" style="width:100%; height:781px; display:none" cellpadding="0px" cellspacing="0px">
<tr>
<td style="width: 50%" align="left" valign="top">
<iframe id="iframe1" runat="server" height="1000px" width="100%" > </iframe>
</td>
<td align="left" valign="top" style="width:50%">
<iframe id="iframe2" runat="server" height="1000px" width="100%" > </iframe>
</td>
</tr>
</table>
 
Thanks in adnvance
Thav