voluntarily produce an error with DBCC CheckDb Would anyone know how I can make DBCC CheckDB produce an error? 
I'm testing a script and need DBCC Checkdb in the simplest mode to return an error, also while trying to repair and when trying to go into single user mode... 

The simple dbcc checkdb command thant I'm using is part of a batch file and is as follows:

OSQL -S MYPC -E -d MyDB -l 10 -Q "DBCC CHECKDB(AG_DB_STORESQL)" -b -o c:\MyFolder\MSSQL_DB_CHECK.Log


If no errors are found the script ends.  If errors are found, the script tries to fix them with the REPAIR_REBUILD option and if that fails the script tries to fix them with REPAIR_ALLOW_DATA_LOSS option.  Obviously, before trying to Repair the script attempts to put the DB in Single user mode (which is also error trapped) 

So All I'm looking for is a way to cause DBCC CheckDB to return an error.
Would anyone know how I can make DBCC CheckDB produce an error?


Use the lethal dbcc writepage ({'dbname' | dbid}, fileid, pageid, offset, length, data [, directORbufferpool]) ON a TEST (NON-PROD) fully sandbox environment.


  The purposes of DBCC WRITEPAGE are:
  
  
  To allow automated testing of DBCC CHECKDB and repair by the SQL Server team.
  To engineer corruptions for demos and testing.
  To allow for last-ditch disaster recovery by manually editing a live, corrupt database.
  


Apart from "The Guru" Paul Randal, @SteveStedman has a good series of Database Corruption Challenge (with solution - but refer it later once you try to address it by yourself).