Adding Last Name for Child on H4 Visa

[pkg234]

My child does not have last name in his passport. He will be going to school and I learnt that not having last name in US is problematic. 

 

Passport: Given Name = Manan, Family Name= <empty>

H4 visa: First Name=FNU, Last Name=Manan. H4 is valid until 2016.

 

If I change the name on Passport from Family Name: <empty> to Family Name: Goyal, 

 

Q1. Do I need to take any action on VISA? 

 

Q2. Will he be able to travel to US with his New Passport (Name changed) and Old Passport with H4 VISA (old name)?

 

Q3. Does he need any additional docuemnt at the Port of Entry in US?

 

 

I'd appreciate help here.

Thanks,

Pankaj