html dom id as number code example

Example 1: js get id value

var element = document.getElementById("YourElementId");
var value_element = document.getElementById("YourElementId").value;

Example 2: how do i set an id for a div in js

All currently used browsers:
element.id=id;
myElement.id=newId;

element.className=class;
myElement.className=newClassName;