thx steve for the link,
after i turn off the IE friendly message, the following message appears
The XML page cannot be displayed
Cannot view XML input using style sheet. Please correct the error and then click the Refresh button, or try again later.
Invalid at the top level of the document. Error processing resource 'http://localhost/NewMofa/WS/Service.asmx'. Line 1, Po...
This is a marker file generated by the precompilation tool, and should not be deleted!
^
While if i create new virtual directory on same level of my website every thing works fine ,
P.S WS and website have the same IP.