Please refer to this code to override a component definition.
<script type="text/javascript">
(function($){
var plugin = $.fn.textbox;
$.fn.textbox = function(options, param){
if (typeof options == 'string'){
return plugin.call($(this), options, param)
}
return this.each(function(){
plugin.call($(this), options, param);
var opts = $(this).textbox('options');
$(this).next().addClass(opts.cls)
})
}
$.fn.textbox.defaults = plugin.defaults;
$.fn.textbox.methods = plugin.methods;
$.fn.textbox.parseOptions = plugin.parseOptions;
})(jQuery)
</script>