Help with simple authentication and cookie setting

I was working on cookies and authentication and I realized, I don't know how to instantiate a PHP function onclick. I've included some code below for a very rudimentary authentication script. I think you'll see, there are two submits - they both work right now. I want the 2nd submit to process the function that sets the cookie.

If anyone has a few seconds to look it over and point me the right way, your help would be VERY appreciated. PHP.net was no help this time.


<?php
/*
simple PHP Authentication script
*/

$password = "password1";

function cookie()
{
setcookie ("cookie1",$auth,time()+2592000);
}

if (isset($cookie1)) {
echo "Verifying password...<br>n";
if ($auth != $password) {
echo "<title>login</title>";
echo "<form method=post action=$PHPSELF>n";
echo "Please enter a password <input type=password maxsize=100 name=auth>n";
echo "<p>";
echo "<input type="submit" value="Enter codeShare">n";

//The next three lines DO NOT work. I don't know how to start the function on the click. Help!

echo "<p><input type="submit" value="Remember Me" onclick="";
cookie();
echo "">n";
echo "<p><p>";
}
}
elseif (empty($auth)) {
echo "<title>login</title>";
echo "<form method=post action=$PHPSELF>n";
echo "Please enter a password <input type=password maxsize=100 name=auth>n";
echo "<p>";
echo "<input type="submit" value="Enter codeShare">n";

//Same deal...

echo "<p><input type="submit" value="Remember Me" onclick="";
cookie();
echo "">n";
echo "<p><p>";
}
elseif ($auth !== $password) {
echo "<title>login</title>";
echo "<font color=red>Incorrect password!</font><p>n";
echo "<form method=post action=$PHPSELF>n";
echo "Please enter a password <input type=password maxsize=100 name=auth>n";
echo "<p>";
echo "<input type="submit" value="Enter codeShare">n";

//Same deal...

echo "<p><input type="submit" value="Remember Me">n";
echo "<p><p>";
}
else {
?>

//go on processing HTML…

<?
}
?>

You can't use the onclick property to call a PHP function. PHP is server side, the onclick property can only call client side scripts (such as javascript).