Imitation webQQ-<1>Email Verification_PHP Tutorial designed by php+js+mysql

Recently I used php+js+mysql to design a course imitating webQQ, and gained a lot. Now I will summarize the key technologies for everyone to learn and communicate.

<1>Email verification

When the user registers, they will enter their email address in the text box. At this time, the onblur and onchange events of the text box are used to use Ajax refresh-free technology to determine whether the email address entered by the user is legal and whether it conflicts with the registered email address.

Js code

[html]
function checkEmail(Email)
{ 
var xmlhttp;
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
If(xmlhttp.overrideMimeType)
{//Set MIME category
xmlhttp.overrideMimeType("text/xml");
}  
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
var url="checkEmail.php?email="+document.getElementById("email").value; //Go to checkEmail.php for verification
xmlhttp.open("GET",url,true);
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{ 
         document.getElementById("error1").innerHTML=xmlhttp.responseText;
}  
}
xmlhttp.send(null);
}
function checkEmail(Email)
{
var xmlhttp;
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
If(xmlhttp.overrideMimeType)
{//Set MIME category
xmlhttp.overrideMimeType("text/xml");
}
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
var url="checkEmail.php?email="+document.getElementById("email").value; //Go to checkEmail.php for verification
xmlhttp.open("GET",url,true);
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
Document.getElementById("error1").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.send(null);
}

PHP code

[php]
header('Content-Type:text/html;charset=GB2312'); //Encoding mode setting
include("conn.php");
$email=$_GET["email"];
$len=strlen($email);
if($email==null)
{
echo "*The email cannot be empty!";
}
else
{
If($len>50)
                                                                                      echo "*The email address should not exceed 50 characters!";
        } 
      else  
                                                                   if(eregi("^[_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3}$",$ email)) //Use regular expression to verify email in php
                                                                                         $sql="select * from user where email='$email'";                     $result = mysql_query($sql);
                    $num=mysql_num_rows($result);
If($num>0)
                                                                                                                                                                                                echo "*This email address is already in use!";
                                                                                                                                                                                                              else                                                                                                                                                                                               echo "*Email is available!";
                                                                                                                                                                           
                                                                                                                                                                                                         else                                                                                                                                                                                                                                                                                              echo "*This email is not available!";
                                                                                                                                                      }
?>
header('Content-Type:text/html;charset=GB2312'); //Encoding mode setting
include("conn.php");
$email=$_GET["email"];
$len=strlen($email);
if($email==null)
{
echo "*The email cannot be empty!";
}
else
{
If($len>50)
{
              echo "*The email address should not exceed 50 characters!";
}
else
{
if(eregi("^[_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3}$",$ email)) //Use regular expression to verify email in php
          {
          $sql="select * from user where email='$email'";           //Connect to the database to query to see if the email is used
                       $result = mysql_query($sql);
                    $num=mysql_num_rows($result);
If($num>0)
                                              {
echo "*This email address is already in use!";
}
       else
          {
                 echo "*Email is available!";
}

}
      else
          {
echo "*This email address is not available!";
}  
}  
}
?>

After learning about email verification, I think other verifications should be very simple! (To be continued)

Excerpted from wyzhangchengjin123