There are two ways to accomplish this task:
But this method is not suitable for Firefox or other browsers that do not support ActiveXObject.
Therefore I recommend to use
Way 2: Using Header method
Generate header in the page that you want to export as Excel sheet, with content below:
<%Response.Write("<meta http-equiv=Content-Type content=text/html;charset=big5>") %><%Response.ContentType="application/vnd.ms-excel"%>
And of course, you still need to put data you want to export as Excel sheet under the header. It's very simple!