Tengo un codigo php de un login, me gustaria poder agregarle un poco de jquery para poder validarlo al formulario.
Este es mi codigo php del login
Código PHP:
<?php
//signin.php
include 'connect.php';
echo '<h3>Iniciar Sesion</h3><br />';
//first, check if the user is already signed in. If that is the case, there is no need to display this page
if(isset($_SESSION['signed_in']) && $_SESSION['signed_in'] == true)
{
echo 'You are already signed in, you can <a href="signout.php">sign out</a> if you want.';
}
else
{
if($_SERVER['REQUEST_METHOD'] != 'POST')
{
/*the form hasn't been posted yet, display it
note that the action="" will cause the form to post to the same page it is on */
echo '<form method="post" action="">
Username: <input type="text" name="usuario" /><br />
Password: <input type="password" name="password"><br />
<input type="submit" value="Ingresar" />
</form>';
}
else
{
/* so, the form has been posted, we'll process the data in three steps:
1. Check the data
2. Let the user refill the wrong fields (if necessary)
3. Varify if the data is correct and return the correct response
*/
$errors = array(); /* declare the array for later use */
if(!isset($_POST['usuario']))
{
$errors[] = 'The username field must not be empty.';
}
if(!isset($_POST['password']))
{
$errors[] = 'The password field must not be empty.';
}
if(!empty($errors)) /*check for an empty array, if there are errors, they're in this array (note the ! operator)*/
{
echo 'Uh-oh.. a couple of fields are not filled in correctly..<br /><br />';
echo '<ul>';
foreach($errors as $key => $value) /* walk through the array so all the errors get displayed */
{
echo '<li>' . $value . '</li>'; /* this generates a nice error list */
}
echo '</ul>';
}
else
{
//the form has been posted without errors, so save it
//notice the use of mysql_real_escape_string, keep everything safe!
//also notice the sha1 function which hashes the password
$sql = "SELECT
usuario_id,
usuario,
usuario_nivel
FROM
usuarios
WHERE
usuario = '" . mysql_real_escape_string($_POST['usuario']) . "'
AND
password = '" . sha1($_POST['password']) . "'";
$result = mysql_query($sql);
if(!$result)
{
//something went wrong, display the error
echo 'Something went wrong while signing in. Please try again later.';
//echo mysql_error(); //debugging purposes, uncomment when needed
}
else
{
//the query was successfully executed, there are 2 possibilities
//1. the query returned data, the user can be signed in
//2. the query returned an empty result set, the credentials were wrong
if(mysql_num_rows($result) == 0)
{
echo 'You have supplied a wrong user/password combination. Please try again.';
}
else
{
//set the $_SESSION['signed_in'] variable to TRUE
$_SESSION['signed_in'] = true;
//we also put the user_id and user_name values in the $_SESSION, so we can use it at various pages
while($row = mysql_fetch_assoc($result))
{
$_SESSION['usuario_id'] = $row['usuario_id'];
$_SESSION['usuario'] = $row['usuario'];
$_SESSION['usuario_nivel'] = $row['usuario_nivel'];
}
echo 'Welcome, ' . $_SESSION['usuario'] . '. <br /><a href="index.php">Proceed to the forum overview</a>.';
}
}
}
}
}
?> 
