Changing the keyboard type used on a GUI.TextField

So I've declared a pretty generic GUI.TextField for a search using:

 this.search = GUI.TextField (new Rect (10, 10, 200, 50), this.search, 25);

The idea is: the user types the word he wants to search, tap on go and the search is performed.

However, I've noticed that the keyboard that is presented does not have the "Go", and when I press the "Done" button no event is sent to the Update() (at least none that changes Input.anyKey...), this would make my user have to type the text and then press an additional button to make the search.

Is there any way to circumvent this? Preferably by showing the "Go" button?

Thanks in advance.