<?php
include("config.php");

function getAllVotes($id)
    {
    /**
    Returns an array whose first element is votes_up and the second one is votes_down
    **/
    $votes = array();
    $q = "SELECT * FROM entries WHERE id = $id";
    $r = mysql_query($q);
    if(mysql_num_rows($r)==1)//id found in the table
        {
        $row = mysql_fetch_assoc($r);
        $votes[0] = $row['votes_up'];
        $votes[1] = $row['votes_down'];
        }
    return $votes;
    }

function getEffectiveVotes($id)
    {
    /**
    Returns an integer
    **/
    $votes = getAllVotes($id);
    $effectiveVote = $votes[0] - $votes[1];
    return $effectiveVote;
    }

$id = $_POST['id'];
$action = $_POST['action'];

//get the current votes
$cur_votes = getAllVotes($id);

//ok, now update the votes

if($action=='vote_up') //voting up
{
    $votes_up = $cur_votes[0]+1;
    $q = "UPDATE entries SET votes_up = $votes_up WHERE id = $id";
}
elseif($action=='vote_down') //voting down
{
    $votes_down = $cur_votes[1]+1;
    $q = "UPDATE entries SET votes_down = $votes_down WHERE id = $id";
}

$r = mysql_query($q);
if($r) //voting done
    {
    $effectiveVote = getEffectiveVotes($id);
    echo $effectiveVote." votes";
    }
elseif(!$r) //voting failed
    {
    echo "Failed!";
    }
?>