PLEASE HELP, Problems with creating new users in database - php

Question

This is my first (of many, hopefully) questions. I am creating a simple login system for a site I'm working on for uni and I have a page that allows the client to add a new user to the database;
<?php
//INSERT//
$host="localhost";
$username="root";
$password="";
$db_name="login";
$tbl_name="members";
//variables//
$myusername=$_POST['myusername'];
$mypassword=$_POST['mypassword'];
mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("$db_name")or die("cannot select DB");
$query = "INSERT INTO members VALUES ('','myusername','mypassword'')";
mysql_query($query);
echo ''.$_POST['myusername'].' has been added as a new user'.'<br/>' ;
mysql_close();
?>
This echo's that "myusername" has been added as a new user, though it doesn't insert anything into the 'members' table. Why is this? It appears to be working ok. I've had to insert an temporary user with an insert script for the time being which works but I really need the user to have the ability to do this themselves. Here is the script I used that works:
<?php
$user="root";
$password="";
$database="login";
mysql_connect('localhost',$user,$password);
#mysql_select_db($database) or die( "Unable to select database");
$query="INSERT INTO `members` VALUES (1, 'kerr', '1234')";
mysql_query($query);
mysql_close();
?>
I hope this makes sense. Thank in advance! Kerr

Answer 1

Set 'members' table 'id' column to auto_increment.
try:
$insert = mysql_query($query);
if($insert){
echo ''.$_POST['myusername'].' has been added as a new user'.'<br/>' ;
}
else{
echo mysql_error($insert);
}
Do you have form tag in the HTML file?