jQuery plugin to ‘matchHeight’ of multiple columns with floating elements

matchHeight.js

(function($) {
/**
 *  .matchHeight()
 *    - match heights of multiple columns that use css layout with floating elements
 */
$.fn.matchHeight = function(options) {
    // set the containing element and set elements used as columns
    var defaults = {
        container : '.main',
        columns   : 'div',
        excluded  : '.dontChangeThis, .dontChangeThat',
        fixed     : 200
    };
    var opts = $.extend(defaults, options);
    return this.each(function() {
        var _ = { self : $(this) };
        _.px = {};
        _.cols = $(opts.container+' > '+opts.columns);
        _.cols.each(function(index) {
            _.px.index = $(this).height();
            if ($(opts.excluded).length>0) {
                _.colheight = opts.fixed;
                return;
            } else {
                if (index < 1) {
                    _.colheight = _.px.index;
                } else {
                    if (_.px.index > _.colheight) {
                        _.colheight = _.px.index;
                    }
                }
            }
        }).each(function(index) {
            $(this).css({ height : _.colheight });
        });
    });
};
})(jQuery);

//
// Call the plugin on a containing layout element with multiple columns
//

/**
 * Stuff to do as soon as the DOM is ready
 *  - enable plugin behavior(s)
 */
$(function() {
    $('.main-container')matchHeight({
                container : '.main',
                columns   : 'div.cols',
                excluded  : 'body.page2, div.noColumns',
                fixed  : 200
     });
    // or us the defaults
    // $('.container').matchHeight();
});