URGENT : Is it possible setting the mimetype for UploadUIElement

Hello,

I have developed an application in web Dynpro which has an FileUpload UI element.

I want when the user clicks on the browse button for selecting any file to the uploaded, the file type in the pop up window is "All Files" by default.

I want it to be only "XML Type" by default such that the user is prevented from selecting any other file.

I have tried setting the mimetype but it is not working.

Kindly help me with this as its very urgent

Thanking You,

Vishal Doshi.