I also search table sys.sql_modules, which contains the code for all sys.objects members of type P, RF, V, TR, FN, IF, TF, and R.
If you want to check for use in a job step, also check table sysjobsteps (msdb.dbo.sysjobsteps), column "command".
SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".