Enable javascript validation in eclipse luna

Question

Sometime ago I asked this question: Enable javascript validation for eclipse

I wanted eclipse to highlight javascript errors/warnings.. The problem as you can see in

Answer 1

Steps to enable/disable validators in your project or workspace:

• Click Window > Preferences and select Validation in the left pane. The Validation page of the Preferences window lists the validators available in your project and their settings.

• To enable individual validators, clear the check boxes next to each
  validator that you want to enable. Each validator has a check box to specify whether it is enabled for manual validation or on a build.

• Click OK.

Also there is an alternative solution available. Do check this out.