【 tulaoshi.com - Web开发 】
                             
                            代码如下: 
!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" 
html xmlns="http://www.w3.org/1999/xhtml" 
head 
title/title 
script src="js/Jquery1.7.js" type="text/javascript"/script 
script type="text/javascript" 
$(function () { 
$('#txtUserName').blur(function () { 
$.ajax({ 
type: "post", 
contentType: "application/json", 
url: "WebService1.asmx/ValidateUser", 
data: "{username:'" + $('#txtUserName').val() + "'}", 
success: function (result) { 
$('#spinfo').text(result.d); 
} 
}) 
}) 
}) 
/script 
/head 
body 
div 
用户名input type="text" id="txtUserName" /span id="spinfo"/spanbr / 
密码input type="text" id="txtPwd" / 
/div 
/body 
/html