gistfile1.js

var rwhitespace = /\s+/;

// These hooks are used by animate to expand properties
$.each({
    margin: "margin*",
    padding: "padding*",
    borderWidth: "border*Width"
}, function( property, expandTemplate ) {

    // order is important!
    var cssExpand = [ "Top", "Right", "Bottom", "Left" ];

    $.cssHooks[ property ] = {
        expand: function ( value ) {
            var i,
                type = $.type( value ),

                // assumes a single number if not a string
                parts = type === "string" ? value.split( rwhitespace ) : [ value ],
                expanded = {};

            for ( i = 0; i < 4; i++ ) {
                expanded[ expandTemplate.replace("*", cssExpand[i] ) ] =
                    parts[ i ] || parts[ i - 2 ] || parts[ 0 ];
            }

            return expanded;
        }
    };
});