<?php
$dbservername = "127.0.0.1";//change
$dbusername = "root";//change
$dbpassword = "";//change
$dbname = "DB_Name";//change

$con = mysql_connect($dbservername, $dbusername, $dbpassword);

if(!con)exit();
$now = strtotime("now");

mysql_select_db($dbname, $con);

$query = "SELECT * FROM players"; //------here name of table

$result = mysql_query($query) or die(mysql_error());

while($row = mysql_fetch_array($result))
{
switch($row["lastonmonth"])//---------here the name  column which stores last month
{
case 1: 
$mon = "January";
break;
case 2:
$mon = "February";
break;
case 3:
$mon = "March";
break;
case 4:
$mon = "April";
break;
case 5:
$mon = "May";
break;
case 6:
$mon = "June";
break;
case 7:
$mon = "July";
break;
case 8:
$mon = "August";
break;
case 9:
$mon = "September";
break;
case 10:
$mon = "October";
break;
case 11:
$mon = "November";
break;
case 12:
$mon = "December";
break;
}
$ld = $row["lastondate"];//---------here the name  column which stores last date
$ly = $row["lastonyear"];//---------here the name  column which stores last year
$last = strtotime("$ld $mon $ly");
$dif = $now - $last;
if($dif < (60 * 60 * 24 * 30 * 4))continue;//4 months
$nn = $row["username"];//-----------------------------------here the name of column storing player name
mysql_query("DELETE  players WHERE username='$nn'");//--------here name of table and also the column name which stores player name
}
mysql_close($con);
?>