<hbox style="border-style: solid; border-color: yellow; margin: 0px; padding: 0px;">
    <label id="sb_notes_label" value="some text" />
</hbox>

label#sb_notes_label {
    cursor: pointer;
    color: white;
    -moz-transform:  rotate(-90deg);
    border-color: white;
    border-style: solid;
    margin: 0px;
}