login(esempio).php

<html>
<head>
<style>
body {
background-color: lightblue;
font-family: Arial, Helvetica, sans-serif;
}
* {
box-sizing: border-box;
}
.container {
padding: 16px;
background-color: white;
}
input[type=text], input[type=password] {
width: 100%;
padding: 15px;
margin: 5px 0 22px 0;
display: inline-block;
border: none;
background: #f1f1f1;
}
input[type=text]:focus, input[type=password]:focus {
background-color: #ddd;
outline: none;
}
hr {
border: 1px solid #f1f1f1;
margin-bottom: 25px;
}
.registerbtn {
background-color: #04AA6D;
color: white;
padding: 16px 20px;
margin: 8px 0;
border: none;
cursor: pointer;
width: 100%;
opacity: 0.9;
}
.registerbtn:hover {
opacity: 1;
}
a {
color: dodgerblue;
}
.signin {
background-color: #f1f1f1;
text-align: center;
}
}
</style>
</html>
<?php
if(empty($_POST['invia'])){
echo"<FORM ACTION='".$_SERVER['PHP_SELF']."'METHOD='POST'>";
echo "<center>";
echo"<TABLE><TR><TD>email<TD><INPUT TYPE='text'NAME='email' placeholder='email...'>";
echo"<TR><TD>password<TD><INPUT TYPE='text'NAME='password'  placeholder='password...'>";
echo"<TR><TD><INPUT TYPE='submit' VALUE='accedi' NAME='invia'>";
echo"<br>";
echo"<a href=registrazione(esempio).php>registrazione</a>";
echo "</center>";
echo"</TABLE></FORM>";
}
$con=new mysqli("localhost","root","","esempio");
if(mysqli_connect_errno()){
echo("connesione_non_effetuata:".mysqli_connect_errno()."<BR>");
exit();
}
$email=isset($_POST['email'])?$_POST['email']:'';
$password=isset($_POST['password'] )? $_POST['password']:'';
$sql="SELECT * FROM registrazione WHERE email='$email' AND Password='$password'";
$ris = $con->query($sql) or die ("Query fallita!");
$conta=mysqli_num_rows($ris);
if($conta==1){
session_start();
$_SESSION['email'] = $email;
$_SESSION['password'] = $password;
header("Location:homepage.html");
}
else{
echo "Identificazione non riuscita: email o password errati <br/>";
}
?>