Save As Type

[Vrunda Joshi]

Hello,
In my code i am invoking the SaveAs window,for which i want to specify the save as type as '.xls'
Mine is a client-server application, so i get the url of file from server.The things work out well except that, the save as type is still showing ".htm,.html" .
I have given the call as execCommand('SaveAs',false,'filename.xls'),but still it shows the saveas type as '.htm,.html' .i have also tried out ('SaveAs',false,'.xls') but it diplayes empty file name box and saveas type is not changed,
how do i do this?
thanks in advance