Insert item to RadComboBox via Javascript error

[Gabriel]

I'm trying to add a new item to a RadComboBox via javascript and I'm getting a weird error.

it says "The object does not support such property or method" when doing "new Telerik.Web.UI.RadComboBoxItem()" 
It is really weird so I decided to open a "quiick watch" window and started to evaluate the Telerik.Web.UI object. As I expected, the "RadComboBoxItem" is not present.

How do I add an item to a RadComboBox via Javascript?

thanks

[Gabriel]

Don't worry, I figured out why this happened. I had visible=false on the control xD