mes/WebContent/resource/ext/4.2/simple.css

.x-button-icon-query {
	background-image: url('../../images/query.png')
}
.x-button-icon-excel {
	background-image: url('../../images/excel.png')
}
.x-button-icon-close {
	background-image: url('../../images/icon/trash.png')
}