<select onchange="for(i=0;i<this.length;i++){if(this.options[i].selected){DynamicURL.src=this.options[i].value;}}">
<option value="Http://192.168.100.100">...</option>
...
<option value="Http://192.168.100.200">...</option>
</select>
<iframe id="DynamicURL" src="<%=strURL%>">
<option value="Http://192.168.100.100">...</option>
...
<option value="Http://192.168.100.200">...</option>
</select>
<iframe id="DynamicURL" src="<%=strURL%>">
<iframe src="xxx.jsp" name="frame1" width=100 height-100 frameborder=0 marginwidth=0 marginheight=0 scrolling=no></iframe>
</td>用javascript动态改变连接
<script>
function changeSrc(url)
{
parent.frame1.src=url;
}
</script>