Skype Vi fails making a phone call

Skype Vi from here https://decibel.ni.com/content/docs/DOC-1287

I exactly followed the steps written the web page. When I run it, it does have skype making a call, but the skype hang up after only a few seconds and shows the message "call weitong_cellphone, no answers".   Labview doesn't show any errors.

While with skype itself, I can paly a call to  the phone number successfully.