Gourdboy

function isRegionOverlap(region1, region2) {
    var min = Math.min;
    var max = Math.max;
    var left   = max(region1.left,region2.left);
    var top    = min(-region1.top,-region2.top);
    var right  = min(region1.right,region2.right);
    var bottom = max(-region1.bottom,-region2.bottom);
    return right > left && top >  bottom;
}

Gourdboy

/**
 * Fetches and inserts a script into the page before the first
 * pre-existing script element, and optionally calls a callback
 * on completion.
 *
 * [TODO] Make this a module of its own so it can be used elsewhere.
 * 
 * @param  {String}   src      source of the script
 * @param  {Function} callback (optional) onload callback
 */