City cars wanted to validate their web design code. what should they use?

.I believe, they should use Server-side scripting language 
Server-side scripting language is used to validat the input that being submitted to the server using server side scripting languages such as ASP.Net, PHP etc
After the validation is complete, a new dynamic web page will be automatically generated.

Ongoing civil wars western roman empire finally collapsed476 c.e. romulus, the last of theroman  emperors in  the west, was overthrown by the germanic leader odoacer, who became the first barbarian to rule in rome. the order that the  roman empire  had brought towestern  europe for 1000 years was no more.