accessing share folder did not ask username

[Guest Adnan]

i am using windows server 2003 for domain controller. i have a shared

folder to users to access the folder. but when i access using one

username it connected to the folder. but when i want to connect using

different user name it did not ask user name and password. can any

body help me that it always ask for username and password whenever i

want to connect to the share folder.