problem while performing form authentication

Hi,
 I am facing prob while doing form authentication,I am doing login validation on login page by using  connected architecture model and using 
<authentication mode="Forms"> <forms loginUrl="LoginPage.aspx"> </forms> </authentication> <authorization> <deny users="*"></deny> </authorization>
but it is not working and giving error in connecting with sql server 2005,plz ans and if you have a proper code then pz post and with steps 
 

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