If you want to take a backup from existing database here is a simple TSQL backup command :
BACKUP DATABASE [NorthWind] TO
DISK = N'c:\backup.dat'
WITH NOFORMAT, NOINIT, NAME = N'Northwind Backup'
See the syntax here :
http://msdn.microsoft.com/en-us/library/ms186865.aspx[
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To restore back the data use this command :
RESTORE DATABASE [Northwind] FROM DISK = N'c:\backup.dat' WITH FILE = 1, NOUNLOAD, REPLACE, STATS = 10
Hope it helps.