<h3>Arrear Billing</h3>
<center>

<?php
$tbl = "el_billing";

$recal = $_REQUEST["recal"];
$ext = $_REQUEST["ext"];
$month = $_REQUEST["month"];

if (!$month) $month = previous_month();//date("M-Y");

echo "<font size='+1'>[ </font>";
if ($ext == 1) {
        echo "<a href='?pg=$pg&month=$month&ext=0'>Internal</a> | <font color='red' size='+1'>External</font>";
} else {
        echo "<font color='red' size='+1'>Internal</font> | <a href='?pg=$pg&month=$month&ext=1'>External</a>";  
}       
echo "<font size='+1'> ]</font>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Month <select name='month' onchange=\"javascript: document.location.href='?pg=$pg&ext=$ext&month='+this.value\">";
$rs = mysql_query("select distinct month from el_reading order by id desc");
while ($o = mysql_fetch_object($rs)) {
	echo "<option value='$o->month'";
	if ($o->month == $month) echo " selected";
	echo ">$o->month</option>";
}
echo "</select>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";

if ($month != previous_month()) {
	echo "Calculate <font size='+1'>[ </font><a href='?pg=$pg&month=$month&ext=$ext&recal=2'>Arrear</a><font size='+1'> ]</font>";
}
echo "<input type='hidden' name='ext' value='$ext'>";

$rs = mysql_query("select * from el_config");
if (mysql_num_rows($rs)) {
	$o = mysql_fetch_object($rs);
	$unitrate = $o->unitrate;
	$fixedrate = $o->fixedrate;
	$plrate = $o->plrate;
	$edrate = $o->edrate;
	$rscrate = $o->rscrate;
	$arrearrate = $o->arrear_rate;
}

if ($recal == 2) {
	$subsidymode = 'None';
	$subsidy = 0.00;
        $rs = mysql_query("select * from $tbl where month='$month' order by id");
        while ($o = mysql_fetch_object($rs)) {
		$id = $o->id;
		$unitrate = $o->unitrate;
		$subsidy = $o->subsidy;
		$subsidymode = $o->subsidymode;
		$consumedunits = $o->curreading - $o->prevreading + $addunits;
		$consumedcharge = $consumedunits * $unitrate;
        	$arrear = 0.00;
		
		//calculate arrear
 
                if ($subsidymode == 'Rupees') {
			$arrearcharge = $consumedcharge + ($consumedunits * $arrearrate);
			if ($arrearcharge > $subsidy) {
				$arrear = $arrearcharge - $consumedcharge;
			}
                } else if ($subsidymode == 'Units') {
			if ($consumedunits > $subsidy) {
                       		$arrear = ($consumedunits - $subsidy) * $arrearrate;
			}
                } else if ($subsidymode == 'None') {
                        $arrear = $consumedunits * $arrearrate;
		}

		//update arrear field in the table
		mysql_query("update $tbl set arrear=$arrear where id=$id");
	}
}

if ($ext == 1) {
	include "elexternalarrears.inc";
} else {
	include "elinternalarrears.inc";
}

?>
</center>