Checkbox modified() and other controls enabled in Dynamics AX

I override method modified() of checkbox. I would like to get other control (field) enabled in form if this checkbox is clicked.

    public boolean modified()
    {
    boolean ret;


    if(ManualAssetId.value()== NoYes::Yes)
    {
        Identification_AssetId.enabled(true);
        ret = super();
    }
    else
    {
        Identification_AssetId.enabled(false);
        ret = super();
    }

    return ret;
}

But this field Identification_AssetId is not getting enabled in the form. Why?