Checking for a specific character string

[aaronbh]

Hello,
Im a very new user and my question is as follows:
I would like to check the contents of a *.txt file for a string of characters ie. 333333333 or 999999999.  IF this character string exsists this file should be deleted.  I would like to thank anyone in advance for your asistance.
Aaron

[Oleg]

See this example. The task searches substring in *.txt files and shows the message.