Dynamically changing class name based on window size

Question

I am using Twitter Bootstrap to create a responsive site using the following layout (simplified for this question):

<div class="container-fluid">
    <div class="row-fluid">
        <!-- Left menu -->
        <div class="span2">
            <div class="sidebar-nav">
                MENU CONTENT GOES HERE
            </div>
        </div>

        <!-- Content -->
        <div id="mainContent" class="span7">
            MAIN CONTENT GOES HERE
        </div>

        <!-- Right column -->
        <div id="rightColumn" class="span3 hidden-phone hidden-tablet">
            RIGHT COLUMN GOES HERE
        </div>
    </div>
</div>

When the browser window resizes to tablet size, the rightColumn div is hidden as expected - but it leaves white space next to the mainContent div (with a size of span3).

I would like the mainContent div to expand to full width (so it fills out matches span10 in size).

I am using the following jQuery code to dynamically change the class name for the mainContent div to achive this (and it works as expected):

$(document).ready(function() {
    var $window = $(window);

        // Function to handle changes to style classes based on window width
        function checkWidth() {
        if ($window.width() < 980) {
            $('#mainContent').removeClass('span7').addClass('span10');
            };

        if ($window.width() >= 980) {
            $('#mainContent').removeClass('span10').addClass('span7');
        }
    }

    // Execute on load
    checkWidth();

    // Bind event listener
        $(window).resize(checkWidth);
});

My question: is this the preferred way to handle changes to spans in Twitter Bootstrap when the browser window resizes? Or should I just change the CSS for span7 for tablet screen sizes to match that of span10?

Answer 1

I will answer it myself: I removed the Javascript code and replaced it with this simple change to the Bootstrap CSS to change the width of span7 to the same width as span10 for tablet screen sizes:

@media (max-width: 979px) and (min-width: 768px) {
    .row-fluid .span7 {
    width: 82.87292817100001%;
    }
}