简单示例：AJAX结合PHP代码实现登录

haidong

<><STRONG><FONT size=2> 【PHPChina讯】 <U><STRONG>javascript</STRONG></U>:tagshow(event, 'HTML');" href="javascript:;" target=_self&gt;<U><STRONG>HTML</STRONG></U></A>部分：</FONT></STRONG><BR></P><>&lt;html&gt;<BR>&lt;head&gt;<BR>&lt;scrīpt language="javascrīpt"&gt;<BR>function postRequest(strURL){<BR>var xmlHttp;<BR>if(window.XMLHttpRequest){ // For Mozilla, Safari, ...<BR>var xmlHttp = new XMLHttpRequest();<BR>}<BR>else if(window.ActiveXObject){ // For <U><STRONG>Internet</STRONG></U> Explorer<BR>var xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");<BR>}<BR>xmlHttp.open('POST', strURL, true);<BR>xmlHttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');<BR>xmlHttp.onreadystatechange = function(){<BR>if (xmlHttp.readyState == 4){<BR>updatepage(xmlHttp.responseText);<BR>}<BR>}<BR>xmlHttp.send(strURL);<BR>}<BR><BR>function updatepage(str){<BR>if(str=="yes"){<BR>alert("Welcome User");<BR>}else{<BR>alert("Invalid Login! Please try again!");<BR>}<BR>}<BR><BR>function call_login(){<BR>var username = window.document.f1.username.value;<BR>var password = window.document.f1.password.value;<BR>var url = "login.php?username=" + username + "&amp;password=" +password ;<BR>postRequest(url);<BR>} <BR>&lt;/scrīpt&gt;<BR>&lt;/head&gt;<BR><BR>&lt;body&gt;<BR>&lt;Center&gt;<BR><BR>&lt;form name="f1" ōnSubmit="return call_login();"&gt;<BR>&lt;table border="0" bgcolor="#CCCCCC" cellspacing="1" cellpadding="3" width="316"&gt;<BR>&lt;tr&gt;<BR>&lt;td align="left" colspan="2"&gt;&lt;b&gt;&lt;font size="5" color="#000080"&gt;Login&lt;/font&gt;&lt;/b&gt;&lt;/td&gt;<BR>&lt;/tr&gt;<BR>&lt;tr&gt;<BR>&lt;td align="right" width="124"&gt;&lt;b&gt;&lt;font color="#000080"&gt;User<BR>Name:&lt;/font&gt;&lt;/b&gt;&lt;/td&gt;<BR>&lt;td width="177"&gt;&lt;input type="text" name="username" id="user" size="20" value="" /&gt;&lt;/td&gt;<BR>&lt;/tr&gt;<BR>&lt;tr&gt;<BR>&lt;td align="right" width="124"&gt;&lt;b&gt;&lt;font color="#000080"&gtassword:&lt;/font&gt;&lt;/b&gt;&lt;/td&gt;<BR>&lt;td width="177"&gt;&lt;input type="password" name="password" size="20" value="" /&gt;&lt;/td&gt;<BR>&lt;/tr&gt;<BR>&lt;tr&gt;<BR>&lt;td colspan="2" align="center"&gt;&lt;input type="button" name="a1" value="Login" ōnClick="call_login()"&gt;&lt;/td&gt;<BR>&lt;/tr&gt;<BR>&lt;/table&gt;<BR>&lt;/form&gt;<BR><BR>&lt;/center&gt;<BR>&lt;/body&gt;<BR>&lt;/html&gt;<BR></P><><FONT size=2><STRONG><U><STRONG>HP</STRONG></U>脚本部分login.php：</STRONG></FONT></P><><STRONG><FONT size=2></FONT></STRONG>&lt;?<BR>$username=$_GET["username"];<BR>$password=$_GET["password"];<BR>if($username=="admin" &amp;&amp; $password=="admin"){<BR>echo "yes";<BR>}else{<BR>echo "No";<BR>}<BR>?&gt;</P><>原文地址：</P>