Cannot Login after publishing my website

Hi,

I've published my website and tried to host in my localsystem.Im getting the login page but cannot login to my application.When i click the submit button in the login page,the page simply refreshes and comesback.The page is not showing any error like 'invalid username or password' which i've set for not proper login

Im using visualstudio 2008 and iis 5.1.What could be cause of this error ??