PHP + Ajax checks whether the user name or email has been registered with an instance tutorial. ajax instance tutorial
PHP + Ajax checks whether a user name or email already exists during registration is a common and important function in the forum or membership system. This article describes how to implement this function in the form of an instance. The procedure is as follows:
I. PHP detection page
The check. php Page code is as follows:
<Script type = "text/javascript" src = "jiance. js "> </script> <form name =" myform "action =" "method =" get "> User name: <input name = "user" value = "" type = "text" onblur = "funtest100 () "/> <div id =" test100 "> </div> </form>
Ii. Ajax verification page
The check. js Page code is as follows:
Var xmlHttp; function S_xmlhttprequest () {if (window. activeXobject) {xmlHttp = new ActiveXObject ('Microsoft. XMLHTTP ');} else if (window. XMLHttpRequest) {xmlHttp = new XMLHttpRequest () ;}} function funtest100 () {var f = document. getElementsByTagName_r ('form') [0]. user. value; // get the content of the text box S_xmlhttprequest (); xmlHttp. open ("GET", "jcfor. php? Id = "+ f, true); // open the xmlHttp request. onreadystatechange = byphp; // you are ready to execute xmlHttp. send (null); // send} function byphp () {// judge the status if (xmlHttp. readyState = 1) {// Ajax status document. getElementByIdx_x_x ('test100 '). innerHTML = "loading";} if (xmlHttp. readyState = 4) {// Ajax status if (xmlHttp. status = 200) {// server status var bytest100 = xmlHttp. responseText; // alert (bytest100); document. getElementByIdx_x_x ('test100 '). innerHTML = bytest100 ;}}}
Iii. PHP verification page
The chkfor. php Page code is as follows:
<? Php if ($ _ GET [id]) {sleep (1); $ conn = mysql_connect ('localhost', 'root', ''); mysql_select_db ('test ', $ conn); $ SQL = "SELECT * FROM 'user' WHERE 'name' = '$ _ GET [id]'"; $ q = mysql_query ($ SQL ); if (is_array (mysql_fetch_row ($ q) {echo "user name already exists";} else {echo "user name can be used" ;}}?>
I hope this example will be helpful for PHP program development.
The friend has the PHP + AJAX code to check the user name.
Files include:
Userreg.html (registration page)
Ajaxreg. js (AJAX script and JS script for real-time verification)
Checkuserreg. php (connect to the database and check whether the user name has been registered)
Userreg.html (registration page) copy the PHP content to the clipboard
PHP code:
<Html>
<Head>
<Meta http-equiv = "Content-Type" content = "text/html; charset = UTF-8"/>
<Title> untitled document </title>
<Script language = "javascript" src = "ajaxreg. js"> </script>
<Script language = "JavaScript" type = "text/JavaScript">
Function check () {// when the user name is null
If (document. reg. username. value = ""){
Document. getElementById ('check'). innerHTML = "<font color = red> the user name cannot be blank! </Font> ";
Document. reg. username. focus ();
Return false;
}
If (document. getElementById ('check '). innerHTML = "<font color = red> The number is registed </font> ") {// when The user name has been registered (<font color = red> The number is registed </font> is returned by AJAX)
Document. reg. username. focus ();
Return false;
}
If (document. reg. userpwd. value = "") {// when the password is empty
Document. getElementById ('pwd'). innerHTML = "<font color = red> the user password cannot be blank! </Font> ";
Document. reg. userpwd. focus ();
Return false;
}
If (document. reg. userpwd. value. length <6) {// when the password length is incorrect
Document. getElementById ('pwd'). innerHTML = "<font color = red> the password length cannot be less than 6 characters! </Font> ";
Document. reg. userpwd. focus ();
Return false;
}
If (document. reg. reuser ...... remaining full text>
Use javascript ajax php to check whether the registered user name already exists
<Script type = 'text/javascript '>
Var username = $ ('# username'). val ();
$. Post ('xx. php', {username: username}, function (data ){
If (data = 1 ){
Alert ("already exists"); // you can set a span or div to display '{xx'{.html ("already exists ");
}
});
</Script>
Xx. php
$ Username = $ _ POST ['username'];
$ SQL = "select * from user where username = $ username ";
$ Handle = mysql_query ($ SQL );
$ Num = mysql_num_rows ($ handle );
If ($ num> 0 ){
$ Flag = 1;
} Else {
$ Flag = 0;
}
Exit ($ flag );