兼容性问题，求指教

[夏侯颜璨]

做二级联动，发现代码在IE9和360兼容模式不生效，看代码貌似是innerHTML语句的问题，求指教解决方法。

function ld(){
var from=document.getElementById('from');
var city=document.getElementById('city');
var arr = [[],
['1'],
['1','2'],
['1','2','3']];
var option = " ";
if(from.value < 0){
city.innerHTML = option;
return;
}
for(i=0,len = arr[from.value].length;i <len;i++){
option += "<option value="+i+">"+arr[from.value][i]+"</option>";
}
city.innerHTML = option;
}

[夏侯颜璨]

from和city就是两个下拉框

[天际的海浪]

function ld() {
	var from = document.getElementById('from');
	var city = document.getElementById('city');
	var arr = [
		[],
		['1'],
		['1', '2'],
		['1', '2', '3']
	];
	city.options.length = 0;
	if (parseInt(from.value, 10) < 0) {
		return;
	}
	for (var i = 0, len = arr[from.value].length; i < len; i++) {
		city.options.add(new Option(arr[from.value][i],i));
	}
}