sometimes it's needed to check whether there are multiple same
modules in the current page or not to keep one version of the
module or some other checks.

there are many starter kits for visual web
developer to learn asp.net 2 and do the
common scenarios of web development.

to convert bitmap image file to gif file you
have to create bitmap object first.

for creating own exception class,you have to derive your class
from System.Exception class.also you have to implement all
constructors which base class implements.to create own
exception class follow the requirements/recommendations
below-

the following codes uses FileUpload control to
upload file to server.it's a example for
uploading files to the server using asp.net
and c#.

if you have a asp.net web page which is derived
from a master page then you may have trouble
using a form inside your page.It happens because
of your master page using a form.It's a little tricky
to be able to use another form which you need to use.
you have to use a javascript line for that.