Do you put it into a IFrame ? or in a FRAMESET/FRAME ?
I just test
<IFRAME width=600 height=400 src='http://chat.interlatin.com/CuteSoft_Client/Peru/CH_MainForm.Aspx?GuestName=&ChannelId=6f5da959-c651-4128-8726-234e8fd75281'></IFRAME>
and see your result .
I think the problem is the width of the <input> is to large .
You could try to set its size by modify the ch_style.css and skins/normal/style.css .
Regards , Terry .