s$email=$_POST['email'];
$email=mysql_real_escape_string($email);
$status = "OK";
$msg="";
//error_reporting(E_ERROR | E_PARSE | E_CORE_ERROR);
// You can supress the error message by un commenting the above line
if (!stristr($email,"@") OR !stristr($email,".")) {
$msg="Your email address is not correct<BR>"; 
$status= "NOTOK";}



echo "<br><br>";
if($status=="OK"){  // validation passed now we will check the tables
$query="SELECT email,userid,password FROM plus_signup WHERE plus_signup.email = '$email'";
$st=mysql_query($query);
 $recs=mysql_num_rows($st);
$row=mysql_fetch_object($st);
$em=$row->email;// email is stored to a variable
 if ($recs == 0) { // No records returned, so no email address in our table
// let us show the error message
 echo "<center><font face='Verdana' size='2' color=red><b>No Password</b><br>
 Sorry Your address is not there in our database . You can signup and login to use our site. 
<BR><BR><a href='signup.html'> Sign UP </a> </center>"; 
exit;}

// formating the mail posting
// headers here 
        $headers4="admin@sitename.com";  // Change this address within quotes to your address
$headers.="Reply-to: $headers4\n";
$headers .= "From: $headers4\n"; 
$headers .= "Errors-to: $headers4\n"; 
//$headers = "Content-Type: text/html; charset=iso-8859-1\n".$headers;// for html mail 

// mail funciton will return true if it is successful
 if(mail("$em","Your Request for login details","This is in response to your request for login detailst at
 site_name \n \nLogin ID: $row->userid \n 
Password: $row->password \n\n Thank You \n \n siteadmin","$headers"))
{echo "<center><b>THANK YOU</b> <br>Your password is posted to your emil address . 
Please check your mail after some time. </center>";}

else{// there is a system problem in sending mail
 echo " <center>There is some system problem in sending login details to your address. 
Please contact site-admin. <br><br><input type='button' value='Retry' onClick='history.go(-1)'></center>";}
	} 

	else {// Validation failed so show the error message
echo "<center>$msg 
<br><br><input type='button' value='Retry' onClick='history.go(-1)'></center>";}


Download PHP signup, login and forgot password script

As you have seen here we can send the lost password to the email address of the member. But if the password is encrypted and stored then we can't retrieve the lost password, so we will generate one activation key and ask the member to use that to reset the forgot password.