使用逗号分隔多个选择器对同一条样式规则进行指定，从而简化了代码量
.tbl-header, .tbl-header1, .tbl-body, .tbl-body1 {
width: 100%;
position: absolute;
top: 0;
left: 0;
}
.tbl-header, .tbl-header1 {
z-index: 999;
}
$('.tbl-body tbody, .tbl-body1 tbody, .tbl-header tbody, .tbl-header1 tbody').empty();
#table thead, #table1 thead {
background-color: #f1f1f1;
}