<?php
$link = mysqli_connect("localhost", "root", "", "homedb");
// Check connection
if($link === false){ die("ERROR: Could not connect. " . mysqli_connect_error()); }

echo "<center>";echo date('m/d/y');echo "<br />";
   //Assign values to variables

$unit=$_POST['unit'];
$datereceived=$_POST['datereceived'];
$time=$_POST['time'];
$area=$_POST['area'];
$problem=$_POST['problem'];
$action=$_POST['action'];
$compday=$_POST['compday'];
$compmoyr=$_POST['compmoyr'];
$cost=$_POST['cost'];
$charge=$_POST['charge'];
$ordno=$_POST['ordno'];
$id = 'id';
$sql = "UPDATE mainttbl SET
datereceived = '$datereceived', time = '$time', area = '$area', problem = '$problem', action = '$action',
compday = '$compday', compmoyr = '$compmoyr', cost = '$cost', charge = '$charge',
ordno =  '$ordno' WHERE id = '$id' ";

if(mysqli_query($link, $sql)){ echo "record was updated successfully."; }
else { echo "ERROR: Could not able to execute $sql. " . mysqli_error($link); }
// Close connection
mysqli_close($link);
?>