How can I make the row number query work with form submission to a MYSQL database?

[Schmit43]

I have been running weather contests in my facebook weather group using PHPMYADMIN and MYSQL. For over a year now
I have been wondering how to make a row count field appear dynamically with each submission.

Here is an example of one of my entry forms:
http://www.directpaintsaleswa.com/MAR2013/add.php


When the user submits the data is placed into the following table:
http://www.directpaintsaleswa.com/MAR2013/add.php

The database table name is users. So I used the following code in PHPMyAdmin to add the rowcount field:

select @n := @n + 1 rowcount, t.*
from (select @n:=0) initvars, users t

Now the above code added that field nicely incrementing the table rows starting at #1 like I wanted.

My problem is that when a user submits a new table entry into the database, the rowcount of that new entry ends up being "0"

on my add.php file when the user submits a new entry I build an sql string like so to append to the database:

$query = "insert into users 

                set
                	
	                //I want to add a row count here that doesnt start at zero

                    name = '".$mysqli->real_escape_string($_POST['name'])."', 

                    avghigh = '".$mysqli->real_escape_string($_POST['avghigh'])."',
					
					avglow = '".$mysqli->real_escape_string($_POST['avglow'])."',

					num60  = '".$mysqli->real_escape_string($_POST['num60'])."',

					num45  = '".$mysqli->real_escape_string($_POST['num45'])."',

				    num32  = '".$mysqli->real_escape_string($_POST['num32'])."',
					
					max  = '".$mysqli->real_escape_string($_POST['max'])."',
					
					min  = '".$mysqli->real_escape_string($_POST['min'])."',
					
					rain  = '".$mysqli->real_escape_string($_POST['rain'])."',
					
					snow  = '".$mysqli->real_escape_string($_POST['snow'])."',
					
					wind  = '".$mysqli->real_escape_string($_POST['wind'])."',
					
					raindays  = '".$mysqli->real_escape_string($_POST['raindays'])."'";

The database currently has 36 entries. If I put in a 37th and so on, the rowcount just stays at zero for each new entry.
I am not an expert at syntax and have tried several combinations and failed...any help would be appreciated greatly

Thank you in advance, Brian