js复选框获取数据到另一张报表,为什么获取不到呢?

var $span = $('.fr-checkbox-checkon'); //获取选中的复选框  
var $tds = $("td").has($span); //定义选中复选框的单元格   
var $trs = $("tr").has($tds);
for (var i = 0; i < $trs.length; i++) {
var name = $("td:eq(1)", $($trs[i])).find("div").html();
var task1 = $("td:eq(8)", $($trs[i])).find("div").html();
var a = $("td:eq(3)", $($trs[i])).html();
var b = $("td:eq(4)", $($trs[i])).html();
var $iframe = $("<iframe id='inp' name='inp' width='100%' height='100%' scrolling='no' frameborder='0'>");
$iframe.attr("src", "${servletURL}?reportlet=xxx.cpt&op=write"+"&num="+name+"&task1="+task1);
var o = {
title : "",
width : 1799,
height: 850
};
FR.showDialog(o.title, o.width, o.height, $iframe,o);
}