有時候我們希望依照不同的頁面內容

即時動態加載 JS 檔案

以下提供 function

function loadScript(url, callback) {
    // Adding the script tag to the head as suggested before
    var head = document.getElementsByTagName('head')[0];
    var script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = url;
    
    // Then bind the event to the callback function.
    // There are several events for cross browser compatibility.
    script.onreadystatechange = callback;
    script.onload = callback;
    
    // Fire the loading
    head.appendChild(script);
    return false;
}