Generate an element object in vanilla javascript

generateElement.js

/*
 * @usage generateElement(_tagName, _attributes, _parent);
 * @param _tagName:String
 * @param _attributes:Object
 * @param _parent:Selector
 * @return an element object
 * @author Mahmoud Elmahdi
*/
function generateElement(_tagName, _attributes, _parent) {
  Element.prototype.setAttributes = function(attrs) {
    for (var idx in attrs) {
      if ((idx == 'styles' || idx == 'style') && typeof attrs[idx] == 'object') {
        for (var prop in attrs[idx]) {
          this.style[prop] = attrs[idx][prop]
        }
      } else if (idx == 'html') {
        this.innerHTML = attrs[idx]
      } else {
        this.setAttribute(idx, attrs[idx]);
      }
    }
  };
  var $tag = document.createElement(_tagName);
  $tag.setAttributes(_attributes);
  _parent.appendChild($tag);
  return $tag;
}

// Example
generateElement('div', {
    'id': 'my-id',
    'class': 'my-class',
    'styles': { /* CSS Properties */ },
    'html': 'text goes here...'
  },
  document.body);