>>sir
>> i developed a web application's using sql server 2005 database but unlukily it was converted to sql server 10 (2008).database.
>>how i recover it. or how i convert it to sql server 2005 again.
>>
>>thanks in advance
>
>Run SSMS on SQL Server 2008, right click on DataBase and choose Properties.
>Click on Options node and change "Compatibility Level"
>
>If that doesn't help:
>Run SSMS on SQL Server 2008, right click on DataBase and choose Tasks.
>From Menu click on "Generate Scripts"
>
>In the wizard:
>1. Select your DB
>2. Check "Script all objects in selected database"
>3. Click on Next
>4. On the next window set ALL desired options esp: Script for Server Version
>5. Follow the wizard.
>
>Then save the generated script and run it on SQL Server 2005.

And then we also may need to import data, if the database contains any data already. Unfortunately, there is no other way to "downgrade" the database otherwise.