Script For Creating A Job Backup

HI guys.

i am trying to create a SP to create a job to take a differential backup. but i m hving a problem . can i any one help me.
what i m doing , is to create job with the same name as the database name ...


EXEC @ReturnCode = msdb.dbo.sp_add_job @job_name= N '' + @DatabaseName + ' Differential Backup',


@enabled=1,

@notify_level_eventlog=0,

@notify_level_email=2,

@notify_level_netsend=0,

@database_name=N '' + @DatabaseName + ',

@notify_level_page=0,

@delete_level=0,

@description=N'No description available.',

@category_name=N'Database Maintenance',

@owner_login_name=N'sa',

@notify_email_operator_name=N'Phil', @job_id = @jobId OUTPUT


IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback


EXEC @ReturnCode = msdb.dbo.sp_add_jobstep @job_id=@jobId, @step_name=N'Differential Backup',

@step_id=3,

@cmdexec_success_code=0,

@on_success_action=1,

@on_success_step_id=0,

@on_fail_action=2,

@on_fail_step_id=0,

@retry_attempts=0,

@retry_interval=0,

@os_run_priority=0, @subsystem=N'TSQL',

@command=N 'BACKUP DATABASE '' + @DatabaseName + ' TO database_Differential WITH DIFFERENTIAL,INIT',

@database_name=N'master',

@flags=0




i m getting this error msg


Msg 102, Level 15, State 1, Procedure CreateDifferentialBackup, Line 23

Incorrect syntax near ''.