Java EE (Java Enterprise Edition) General Discussion

Hi,

In my system MS Office 2007 is installed. I am trying to generating excel sheets from JSP page by setting the content type "application/vnd.ms-excel" in jsp page and as well as in web.xml file. I am getting the below message
The file you are trying to open, 'xxxxxxxx.xls', is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a trusted source before opening the file. Do you want to open the file now?

Then finally the excel file is opening and displaying properly. If in my system MS Office 2003 is installed , then the above message is not coming.
I have changed the content type according to Excel 2007 <%@ page contentType= "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" %> and in web.xml file the mime type to
<mime-mapping>
<extension>xlsx</extension>
<mime-type>application/vnd.openxmlformats-officedocument.spreadsheetml.sheet</mime-type>
</mime-mapping>

even the content type is changed according to office excel 2007 , i am getting the same above message.

My client is asking not to display the above message. So how to prevent that message ?

It's very great if any body reply me as soon as possible.