Yahoo! UI Library

if (!Y.config.doc.documentElement.hasAttribute) { // IE < 8
    Y.Node.prototype.hasAttribute = function(attr) {
        if (attr === 'value') {
            if (this.get('value') !== "") { // IE < 8 fails to populate specified when set in HTML
                return true;
            }
        }
        return !!(this._node.attributes[attr] &&
                this._node.attributes[attr].specified);
    };
}

// IE throws an error when calling focus() on an element that's invisible, not
// displayed, or disabled.
Y.Node.prototype.focus = function () {
    try {
        this._node.focus();
    } catch (e) {
        Y.log('error focusing node: ' + e.toString(), 'error', 'node');
    }
};

// IE throws error when setting input.type = 'hidden',
// input.setAttribute('type', 'hidden') and input.attributes.type.value = 'hidden'
Y.Node.ATTRS.type = {
    setter: function(val) {
        if (val === 'hidden') {
            try {
                this._node.type = 'hidden';
            } catch(e) {
                this.setStyle('display', 'none');
                this._inputType = 'hidden';
            }
        } else {
            try { // IE errors when changing the type from "hidden'
                this._node.type = val;
            } catch (e) {
                Y.log('error setting type: ' + val, 'info', 'node');
            }
        }
        return val;
    },

    getter: function() {
        return this._inputType || this._node.type;
    },

    _bypassProxy: true // don't update DOM when using with Attribute
};

if (Y.config.doc.createElement('form').elements.nodeType) {
    // IE: elements collection is also FORM node which trips up scrubVal.
    Y.Node.ATTRS.elements = {
            getter: function() {
                return this.all('input, textarea, button, select');
            }
    };
}