Read-only combobox (Vaadin 6.7)


I would like to customize readonly combobox.
I want to set a border to my combobox in a readonly mode.

.v-app .v-filterselect.v-readonly .v-filterselect-input
    border: 1px solid #b6b6b6;
    border-top-color: #9d9d9d;
    border-bottom-color: #d6d6d6;
    border-right-color: #d6d6d6;
    color: #464f52;
    opacity: 1.0;

But my problem is the combobox button is invisible
and so the combobox width is not as large as it must be.

Can you help me to fix it.

Thanks in advance,