Magento configurable product default options by attribute label

configurable.phtml

        Product.Config.prototype.fillSelect = Product.Config.prototype.fillSelect.wrap(function(superMethod, element){
            var attributeId = element.id.replace(/[a-z]*/, '');
            var attribute = this.config.attributes[attributeId];
            this.config.chooseText = 'Select ' + this.config.attributes[attributeId].label;
            return superMethod(element);
        });