following select comp ...

System

Hi again,
have problemes to set the value of a select component to a default one :

in my js file - init methode-
i try this code :
var item = IWDatacapture.getItem('/Europe/lang');
var option = item.getOptions();
var defaultvalue = option[0].value;
item.setValue(defaultvalue);
var value = item.getValue();
alert('value on init:'+value);

well my alert gives me a null value ..so strange ..!!