Ajax validates the user name and password of the instance code _ajax related

The example of this article introduced the AJAX authentication username and password of the specific code for your reference, the specific contents are as follows

1.ajax Body part

var xmlrequest; function Createxmlhttprequest () {if (window).
      XMLHttpRequest) {xmlrequest=new XMLHttpRequest (); else if (window.
         ActiveXObject) {try{xmlrequest=new ActiveXObject ("msxm12.xmlhttp");
            catch (e) {try{xmlrequest=new ActiveXObject ("Microsoft.XMLHTTP");
  The catch (e) {}}} function login () {createxmlhttprequest ();
  var user = document.getElementById ("YHM"). Value;
  var password = document.getElementById ("MM"). Value; if (user== "" | |
   password== "") {alert ("Please enter username and password!");
  return false;
  The var url = "check.php?user=" +user+ "&password=" +password;
  Xmlrequest.open ("POST", url,true);
   Xmlrequest.setrequestheader ("Content-type", "application/x-www-form-urlencoded");  Xmlrequest.onreadystatechange = function () {if (xmlrequest.readystate = 4) {if (xmlrequest.status==200) {var msg   
        = Xmlrequest.responsetext; if (msg== ' 1 '){alert (' username or password is wrong! ');
        User= "";
        Password= "";
      return false;
      } else{window.location.href= "index1.html";
 }}} xmlrequest.send ("user=" +user+ "&password=" +password); }

2.html Code

<input placeholder= "username" autofocus= "type=" text "name=" username "> <input placeholder=  
  " password "type=" Password "name=" password ">
  <button id=" DL "onclick=" Login () "> Login </button>

3. Here is the use of SHA1 encryption, your password and database name changes to your own can

<?php
$yhm 1=$_post[' user '];
 $mm 1=$_post[' password '];
@ $DP =new mysqli (' localhost ', ' root ', ' Your password ', ' your database name ');
$yhm 2=sha1 ($yhm 1);
$MM 2=SHA1 ($mm 1);
$query = "SELECT * from Zhuce where yhm= ' $yhm 2 ' and mm= ' $mm 2 '";
$result = $DP->query ($query);
$num = $result->num_rows;
if (! $num) {
  echo "1";
}
 
$DP->close ();
 
? >

The above is the entire content of this article, I hope to help you learn.