User Authentication via web service
I will be writing a desktop based application in Adobe Flex/Microsoft .NET which would be based on web services. I have a coupl eof questions.
1. I wish to know how to authenticate the user i.e. say I create a login sreen in my application and accept the user's sap netweaver user/pwd, now I wish to know if there is already any standard web service that can be user to authenticate? If there is no standard web service then how can I achieve this?
2. The next question is even if I am able to do the first step and authnticate the user, how do I maintain the session i.e. the subsequent web service calls should not ask for user credentials.
Thanks & regards,