staying in same page after submiting form button - php

Question

I'm trying to stay on the same page after submitting a form button.
Depending on the button the user clicks, I want to display certain information on that same page the button was clicked.
For some reason it keeps redirecting me back to my "ask_login.php" page after I click on the button.
I've read around and some people recommend using AJAX or JQuery but I don't really understand much about it. I'd be appreciated if I could get some help. Thanks.
loggedin.php
<?php
$username = $_POST['username'];
$password = $_POST['password'];
if($username && $password) {
//info is provided
$queryget = mysql_query("SELECT * FROM users WHERE id='$username' AND password='$password'");
$numrows = mysql_num_rows($queryget);
if($numrows != 0) {
//something has been found
$_SESSION['id'] = $username;
} else {
echo "Wrong username/password";
echo "<script>alert('Username/Password are wrong');</script>";
echo "<script language='javascript'>window.location = 'ask_login.php';</script>";
}
}
else {
echo "Wrong username/password";
echo "<script>alert('Username/Password are wrong');</script>";
echo "<script language='javascript'>window.location = 'ask_login.php';</script>";
}
?>
<form method="POST" action="">
<input type="submit" name="details" value="Details">
</form>
<form method="POST" action="">
<input type="submit" name="optionB" value="option B">
</form>
<form method="POST" action="">
<input type="submit" name="optionC" value="option C">
</form>

Answer 1

<form action="#">. no action means 'submit to current url', the pound sign mean 'the current document' and should not navigate. though i'm not sure forms semantically allow this.
I would recommend posting the form data over ajax though. Its not hard to do, Jquery offers the most used ajax function and you basically loop though each input in a form and push the value into a uri-encoded string and post that via an ajax call.

Answer 2

I think this following code is not correct...
if($username && $password)
Try this
if(!empty($username) && !empty($password))

Answer 3

i think it shout be
<?php
if($_POST)
{
$username = $_POST['username'];
$password = $_POST['password'];
if($username && $password) {
//info is provided
$queryget = mysql_query("SELECT * FROM users WHERE id='$username' AND password='$password'");
$numrows = mysql_num_rows($queryget);
if($numrows != 0) {
//something has been found
$_SESSION['id'] = $username;
} else {
echo "Wrong username/password";
echo "<script>alert('Username/Password are wrong');</script>";
echo "<script language='javascript'>window.location = 'ask_login.php';</script>";
}
}
else {
echo "Wrong username/password";
echo "<script>alert('Username/Password are wrong');</script>";
echo "<script language='javascript'>window.location = 'ask_login.php';</script>";
}
}
?>
<form method="POST" action="">
<input type="submit" name="details" value="Details">
</form>
<form method="POST" action="">
<input type="submit" name="optionB" value="option B">
</form>
<form method="POST" action="">
<input type="submit" name="optionC" value="option C">
</form>

Answer 4

you can use jquery to process the form
$.post( "test.php", $( "#testform" ).serialize(),function(e){alert(e);} );
test.php
<?php
$username = $_POST['username'];
$password = $_POST['password'];
if($username && $password) {
//info is provided
$queryget = mysql_query("SELECT * FROM users WHERE id='$username' AND password='$password'");
$numrows = mysql_num_rows($queryget);
if($numrows != 0) {
//something has been found
$_SESSION['id'] = $username;
} else {
echo "Wrong username/password";
echo "<script>alert('Username/Password are wrong');</script>";
echo "<script language='javascript'>window.location = 'ask_login.php';</script>";
}
}
else {
echo "Wrong username/password";
echo "<script>alert('Username/Password are wrong');</script>";
echo "<script language='javascript'>window.location = 'ask_login.php';</script>";
}
?>
http://api.jquery.com/jquery.post/
beware, no input validation!
read this page
http://www.php.net/manual/en/function.mysql-real-escape-string.php