WebService on IIS - Write to File

Hi experts;

Is it possible to write to a file in a C#.NET WebService?? When I try to write to a file in a web service method, and then test it on the localhost machine i get a page cannot be found, so i assume some error occurred. Do i need to alter some setting in IIS to allow me to write a file to a directory on the web server?

Directory structure:-

wwwroot
 + WebServices
    + MyWebService
       + bin
       + Log
       - Global.asax
       - Service1.asmx
       ...

So I want to write to a file in the path: ..wwwroot\WebServices\MyWebService\Log\LogFile.txt

MyWebService is the name of the web service i am developing.

thanks!