<?php

// dbConfig.php is a file that contains your
// database connection information. This
// tutorial assumes a connection is made from
// this existing file.
include ("dbconfig.php");


//Input vaildation and the dbase code
if ( $_GET["op"] == "reg" )
{
$bInputFlag = false;
foreach ( $_POST as $field )
{
if ($field == "")
{
$bInputFlag = false;
}
else
{
$bInputFlag = true;
}
}
// If we had problems with the input, exit with error
if ($bInputFlag == false)
{
die( "Problem with your registration info. "
."Please go back and try again.");
}

// Fields are clear, add user to database
// Setup query
$q = "INSERT INTO `dbUsers` (`username`,`password`,`email`) "
."VALUES ('".$_POST["username"]."', "
."PASSWORD('".$_POST["password"]."'), "
."'".$_POST["email"]."')";
// Run query
$r = mysql_query($q);

// Make sure query inserted user successfully
if ( !mysql_insert_id() )
{
die("Error: User not added to database.");
}
else
{
// Redirect to thank you page.
Header("Location: register.php?op=thanks");
}
} // end if


//The thank you page
elseif ( $_GET["op"] == "thanks" )
{
echo "<h2>Thanks for registering!</h2>";
}

//The web form for input ability
else
{
echo "<form action=\"?op=reg\" method=\"POST\">\n";
echo "Username: <input name=\"username\" MAXLENGTH=\"16\"><br />\n";
echo "Password: <input type=\"password\" name=\"password\" MAXLENGTH=\"16\"><br />\n";
echo "Email Address: <input name=\"email\" MAXLENGTH=\"25\"><br />\n";
echo "<input type=\"submit\">\n";
echo "</form>\n";
}
// EOF
?>

<?PHP
$user_name = $_POST['u_name'];
$password = $_POST['pass'];

//db connection string
$db = mysql_connect("localhost","root","pass");
mysql_select_db("my_database",$db);
//replace the above values with your actual database val

//We will now retrive the password from the database
$sql_query = mysql_query("SELECT password FROM user_data WHERE user_name='$user_name'",$db);
$rs = mysql_fetch_row($sql_query);

//comparing passwords
Note before we can compare the password we use md5() to encrypt the $password becuase the password that we retrive from the database is in the encrypted form.
if(md5($password) != $rs[0])
echo "ERROR: Invalid User";
else
echo "Congrats, Password is correct!";
?>