Looking on the internet deeply has found these results:

Happy to be of help is the most popular phrase on the web.

Glad to be of help 1729,000 results on the web	Happy to be of help 128,300,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Always glad to be of help to people of quality, such as yourselves. Glad to be of help, ma'am. Certainly. Glad to be of help. Always glad to help a colleague. Just glad to be of help, Miss Day. Glad to be of help, sir. I'm glad to be of help. I'm glad to be of help.	I'm happy to be of help. We are quite happy to help clear obstacles to reach the modal shift. Happy to help you any way I can. Happy to be of help, Betsy. I'll be happy to help you in one sec. Loosely was happy to help the Italian Linguistics Laboratory investigate the paucity of VUE incidence in France. My wife and the FRG would be happy to help you contact any other relatives, arrange for their transportation. Said he'd be happy to help us out.

Glad to be of help

1729,000 results on the web

Happy to be of help

128,300,000 results on the web

More popular!

I'm happy to be of help.
We are quite happy to help clear obstacles to reach the modal shift.
Happy to help you any way I can.
Happy to be of help, Betsy.
I'll be happy to help you in one sec.
Loosely was happy to help the Italian Linguistics Laboratory investigate the paucity of VUE incidence in France.
My wife and the FRG would be happy to help you contact any other relatives, arrange for their transportation.
Said he'd be happy to help us out.