disable enable constrain mssql

I copied this from http://stackoverflow.com/questions/159038/can-foreign-key-constraints-be-temporarily-disabled-using-t-sql 

-- disable all constraints
EXEC sp_msforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT all"

-- enable all constraints
exec sp_msforeachtable @command1="print '?'", @command2="ALTER TABLE ? WITH CHECK CHECK CONSTRAINT all"