[jQuery] Calling a user-defined function

[cachobong]

How do i use a function like this?

$.clientCoords = function() {
             var dimensions = {width: 0, height: 0};
             if (document.documentElement) {
                 dimensions.width = document.documentElement.offsetWidth;
                 dimensions.height = document.documentElement.offsetHeight;
             } else if (window.innerWidth && window.innerHeight) {
                 dimensions.width = window.innerWidth;
                 dimensions.height = window.innerHeight;
             }
             return dimensions;
        }