样式表达式实现交替显示table行颜色

<heand> <mce:style type="text/css"><!-- tr {background-color:expression((this.sectionRowIndex%2==0)?"#419C33":"#CCEBC7")} --></mce:style><style type="text/css" mce_bogus="1">tr {background-color:expression((this.sectionRowIndex%2==0)?"#419C33":"#CCEBC7")}</style> <mce:style type="text/css"><!-- tr.lightrow td { background-color: #FFFFFF; } tr.darkrow td { background-color: #EFEFEF; } --></mce:style><style type="text/css" mce_bogus="1">tr.lightrow td { background-color: #FFFFFF; } tr.darkrow td { background-color: #EFEFEF; }</style> <table id="main_table"> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> <tr> <td width="100">a</td> <td width="100">b</td> </tr> </table>
提示：您可以先修改部分代码再运行