SaveAs doesn't save the linked file

[archit]

Hi All ,
I have a link in my page which points to an XML file in my tomcat web server. I want that when users click on that link they should get a Save As dialogue box which will save the file.
i tried with the SaveAs function on the OnClick button but that tries to Save te Html page in which that link is not the XML file that link points to. Attaching below the code which I am using . Kindly send in your sugestions as to how to achieve the desired functionality.

out.println(&quot;<br><br><center><b> <a href='downloads/&quot;+filename+&quot; onClick=&quot;document.execCommand('SaveAs')'; return false;&quot;>Get the XML File Generated</a></b></center>&quot;

Thanks in advance
Vikul