With

Get With It!

Use with as a shortcut. In the with block, any methods or properties you use without reference to an object are assumed to be specified in the with object.
Saves typing, but slows execution.

with (Math){
    var numberone = random();
    var numbertwo = random();
    var numberthree = random();
}

...as opposed to...

var numberone = Math.random();
var numbertwo = Math.random();
var numberthree = Math.random();