DOM을 다룰 수 있게 될 때 이벤트를 발생시킵니다. (cross browser)

ondomready.js

function onDOMReady(listener) {
    if(document.readyState) switch(document.readyState) {
        case 'complete':
            listener();
            break;
        case 'interactive':
            /* "interactive" in IE 9 is quite different - we can't handle DOM elements at this time */
            if(!(__MSIE__ = navigator.appVersion.match(/MSIE ([0-9]+\.[0-9]+)/)) || __MSIE__[1] > 9) {
                listener();
                break;
            }
        default:
            document.addEventListener('load', listener);
            document.addEventListener('DOMContentLoaded', listener);
    }
    else {
        // browser seems like way too old (ie < 8.0) - time to give up
        throw 'YourMother: Too old browser!!!';
        return;
    }
}