dom.ready

dom.ready.js

var domReady = function(callback) {
  if(callback && typeof callback === 'function') {
    if(!document.attachEvent || typeof document.attachEvent === 'undefined') {
      document.addEventListener('DOMContentLoaded', function() {
        return callback();
      });
    } else {
      document.attachEvent('onreadystatechange', function() {
        if(document.readyState === 'complete') {
          return callback();
        }
      });
    }
  } else {
    // Do something else
  }
};

main.js

domReady(function() {
  //
});