s:date 标签里的id 值为什么获取不到

[wfghefg]

s:date name="deadline" id="deadline" fieldLabel="有效日期"
colspan="1/2" editable="false" allowBlank="false" /
为什么从这里deadline值获取不到了。是因为这吗
<%@ taglib uri="http://ckeditor.com" prefix="ckeditor"%>
<%@page import="com.ckeditor.CKEditorConfig"%>
我要获取这个时间
function afterSubmitCloseWindow(){
var date = new Date();
var dt = Date.parse(date.format('Y-m-d'));
var validdate = Ext.getCmp('form1').getForm().findField('deadline').getValue();
var validdt = Date.parse(validdate);
if(dt >= validdt){
Ext.Msg.alert("系统提示","输入的有效日期 要大于当前日期");
return;
}else{
// var grantOrgStrs = getGrantOrgStr();
// var grantRangeStrs = getGrantRangeStr();
var url = '/am/bulletin/bulletinAction.do?method=save';
submitForm('form1',url,function(){
closeWindow();
});
}
}