.x-tool-center {
    background-image: url('images/ext-tool-sprites.gif') !important;
    background-position: 0 0;
}
.x-tool-over .x-tool-center {
    background-image: url('images/ext-tool-sprites.gif') !important;
    background-position: -15px 0;
}
.x-tool-trash {
    background-image: url('images/ext-tool-sprites.gif') !important;
    background-position: 0 -15px;
}
.x-tool-over .x-tool-trash {
    background-image: url('images/ext-tool-sprites.gif') !important;
    background-position: -15px -15px;
}