opening in excel sheet

[prajapatisagar Sagar]

<%response.setContentType("application/excel"); 
 response.setHeader("Content-disposition","attachment; filename=leaveDetails.xls");
%>

above is code in jsp page which opens this very page in excel with file name leaveDetails.xls but in some clients computer the filename is orbitary like "weqbbd"

and user is confused while saving this file with arbitory name but when opened this file it is opened with excel that is fine. what is the problem that changed the

name of the file please help thanks in advance