js--表单提交---databox 日期取值和比较

<tr>
<td align="left" height="60px" width="100px">开始时间：</td>
<td class="left" >
<input type="text" id="activity_start_time" name="activity_start_time" style="200px;height:30px" class="easyui-datebox"
data-options="required:true,validType:'length[0,19]'" />
</td>
<td align="right" height="60px" width="100px">结束时间：</td>
<td class="left">
<input type="text" id="activity_end_time" name="activity_end_time" style="200px;height:30px" class="easyui-datebox"
data-options="required:true,validType:'length[0,19]'"/>
</td>
</tr>

function timeEq(str){
var sd=str.split("-");
return new Date(sd[0],sd[1],sd[2]);  ----取值[0]--年  [1]--月  [2]--日
};

function submitData(){
$('#meeting_register_activity_base').form('submit', {
url: "/meeting/actions/register/addActivity.do?actionId=meeting_register_addActivity&activity_id="+activity_id,
onSubmit: function(){
if($("#meeting_register_activity_base").form("validate")){
var start = timeEq($("#activity_start_time").datebox("getValue"));
var end = timeEq($("#activity_end_time").datebox("getValue"));
if(end>=start){
return ;
}else{
$$.showJcdfMessager('提示消息','结束时间不可早于 开始时间', 'info');
return false;
}
}else{
return false;
};
},
success:function(oData){
var data = jQuery.parseJSON(oData); //解析
var errorCode = data.errorCode
if(errorCode==0){
$$.showJcdfMessager('提示消息',data.msg, 'info');
} else{
$$.showJcdfMessager('提示消息',data.msg, 'info');
}

}
});
}