JavaScript set values and model update

[Alexander Panzhin <ja...@balticum-tv.lt>]

I have a problem with JavaScript set values.
<t:selectOneMenu id="moduleSelect" forceId="true" value="#{search.module}">
<f:selectItems value="#{search.modules}" />
</t:selectOneMenu>

Than I add options to this select menu via js.
       var a = document.getElementById("moduleSelect").options;
       a[0] = new Option("","", false);
and so on...

My #{search.modules} also returns a SelectItem list(when appropriate).
But the problem is unless #{search.modules} is not empty, whatever i 
choose update my model with that data.

Is there anything that I'm missing here?

I use Facelets/MyFaces.