PHP Example
Screen shot
Screen shot
Screen shot
Index.php

<html>
<head>
<title>Forget Password</title>
</head>
<body>
<form name=\"frm\" action=\"\" method=\"post\">
<table border=\"1\">
<tr><td align=\"center\" colspan=\"2\"><h3>User Login</h3></td></tr>
<tr>
<td>Enter user_id</td>
<td><input type=\"text\" name=\"id\" /></td>
</tr>
<tr>
<td>Enter password</td>
<td><input type=\"password\" name=\"pwd\" /></td>
</tr>
<tr>
<td colspan=\"2\" align=\"center\"><input type=\"submit\" name=\"btn\" value=\"Login\" /></td>
</tr>
<tr>
<td align=\"right\" colspan=\"2\"><a href=\"forgot.php\">Forgot password</a></td>
</tr>
</table>
</form>
</body>
</html>

forgot.php

<?php
session_start();

// Mysql connectivity and database connectivity
$conn=mysql_connect(\'localhost\',\'root\',\'\') or die(\'Mysql not connected\');
$database=mysql_select_db(\'test\',$conn) or die(\'Database Not connected\');

// To Get New Password Mail New password to user and store new password into database
if(isset($_REQUEST[\'btn-forget\'])){ 

$user_name=$_POST[\'email\'];
$query1=\"select * from tbl_user where user_name=\'$user_name\'\";
$result1=mysql_query($query1);
$rows1=mysql_num_rows($result1);

if($rows1>=1){
$x=array(\"a\",\"b\",\"c\",\"d\",\"e\",\"f\",\"g\",\"h\",\"i\",\"j\",\"k\",\"l\",\"m\",\"n\",\"o\",\"p\",\"q\",\"r\",\"s\",\"t\",\"u\",\"v\",
\"w\",\"x\",\"y\",\"z\",\"A\",\"B\",\"C\",\"D\",\"E\",\"F\",\"G\",\"H\",\"I\",\"J\",\"K\",\"L\",\"M\",\"N\",\"O\",\"P\",\"Q\",\"R\",\"S\",\"T\",
\"U\",\"V\",\"W\",\"X\",\"Y\",\"Z\",\"0\",\"1\",\"2\",\"3\",\"4\",\"5\",\"6\",\"7\",\"8\",\"9\");
   
$user_password=\"\";
   
for($i=0;$i<=8;$i++){
$user_password=$user_password.$x[rand(0,count($x)-1)];
}
   
$query2=\"update tbl_user set user_password=\'$user_password\' where user_name=\'$user_name\'\";
mysql_query($query2);
   
$to=$_REQUEST[\'email\'];
$subject=\"New password\";
$message=\"Your New Password is : $user_password\";
$from=\'admin@ittrainingonline.co.in\';
$headers = \"From: $from\";
   
$result=mail($to,$subject,$message,$from);
   
if($result){
$_SESSION[\'msg\']=\"Your password has been sent to your email\";
}
             
}
else{
$_SESSION[\'msg\']=\"Your Email ID does not exist our database\";
}
}
?>
<html>
<head>
<title>Forget Password</title>
</head>
<body>
<form name=\"frm\" action=\"\" method=\"post\">
<table width=\"362\" border=\"0\">
<tr>
<td align=\"center\" colspan=\"2\">
<?php if(isset($_SESSION[\'msg\'])) {
echo \"<font color=\'green\' size=\'+1\'>\".$_SESSION[\'msg\'].\"</font>\";
unset($_SESSION[\'msg\']);
}
?>
</td></tr>
<tr>
<td align=\"center\" colspan=\"2\">Please enter Email ID to receive password</td>
</tr>
<tr><td height=\"24\" colspan=\"2\" align=\"center\">&nbsp;</td>
</tr>
<tr>
<td>Enter Email ID</td>
<td><input type=\"text\" name=\"email\"  style=\"width:200px;\" /></td></tr>
<tr><td colspan=\"2\" align=\"center\"><input type=\"submit\" name=\"btn-forget\" value=\"Submit\" /></td>
</tr>
</table>
</form>
</body>
</html>

You can download source code here