DS-160 form can be edited after submitted

My friend today went for an interview and there was some mistake on the form. He was told to visit a nearby CyberCafe to edit the submitted form. When he went over there he was charged rupees 300 for editing the submitted form. What he did was just enter the login and password and was able to edit. SO my question is it is editable but how?

plz someone reply to this question so i can come to know about this. if it is editable then it will be really great