How do I block a number

[MaxDunbar58968]

Hi I work in an office and I am getting too many calls from my ex girlfriend. I was wondering how to block a number. I really don’t want to tell my boss about this.  I have a 7900 series version. 
Thank you!!

Not sure if I posted in the correct location. 

[Leo Laohoo]

Read Malicious Call Identification

[Jaime Valencia]

If you're an end user, this is not something you can do by yourself, you need to involve your IT administrator to do this.