//利用元素的load方法更新html
Ext.fly("btnLoad").on('click', function() {
    Ext.fly("lblServerDateTime").load({ url: 'server_time.php' });
});

//利用request更新服务器时间
Ext.fly("btnRequest").on('click', function() {
    Ext.Ajax.request({
        url: 'server_time.php',
        params: {
            type: 'date'
        },
        success: function(response, opts) {
            Ext.fly('lblServerDate').dom.innerHTML = response.responseText;
        },
        failure: function(response, opts) {
            Ext.fly('lblServerDate').dom.innerHTML = '请求失败,错误代码：' + response.status;
        }
    });
});

//AJAX提交整个form表单
Ext.fly("btnRegister").on('click', function() {
    Ext.Ajax.request({
        url: 'register.php',
        form: 'formRegister',
        method:  'POST',
        success: function(response, opts) {
            Ext.fly('lblMessage').dom.innerHTML = response.responseText;
        },
        failure: function(response, opts) {
            Ext.fly('lblMessage').dom.innerHTML = '请求失败,错误代码：' + response.status;
        }

    });
});

//设置所有请求的缺少头部信息
Ext.Ajax.defaultHeaders = {
    'Powered-By': 'extjs.org.cn'
};
//发送并验证服务器得到的头部信息
Ext.fly("btnHeader").on('click', function() {
    Ext.fly("lblHeader").load({ url: 'headers.php' });
});

<?php
if($_POST['type'] == "date")
{
	echo date("Y-m-d");
}
else
{
	echo date("Y-m-d H:i:s");
}
?>

<?php
print_r($_POST);
//TODO
?>

<?php
echo "[HTTP_POWERED_BY] => ".$_SERVER['HTTP_POWERED_BY'];
?>