cosignupback.php

<?php
session_start();
$username = filter_input(INPUT_POST, 'username');
$password = filter_input(INPUT_POST, 'password');
$c_id = filter_input(INPUT_POST, 'c_id');
$c_ph = filter_input(INPUT_POST, 'c_ph');
$email = filter_input(INPUT_POST, 'email');
$address = filter_input(INPUT_POST, 'address');
$r_password = filter_input(INPUT_POST, 'rpassword');
if (!empty($username)) {
    if (!empty($address)) {
        if (!empty($c_ph)) {
            if (!empty($email)) {
                if (!empty($password)) {
                    if ($password == $r_password) {
                        require "dbh.php";

                        $hashedpwd = password_hash($password, PASSWORD_DEFAULT);
                        $sql = "Insert into company(Co_Name,Co_Address,Co_Ph_Number,Co_Email,Co_Pass)
                                   values('$username','$address','$c_ph','$email','$hashedpwd')";

                        if ($conn->query($sql)) {
                            echo "Sign Up successfull.";
                            header("Location: index.php");
                        } else {
                            echo "Error" . $sql . "<br>" . $conn->error;
                        }
                        $conn->close();
                    } else {
                        echo "<script>alert('Password deos not match!');window.location='cosignup.php'</script>";
                    }
                } else {
                    echo "Password should not be empty";
                }
            } else {
                echo "Email should not be empty";
            }
        } else {
            echo "Phone Number should not be empty";
        }
    } else {
        echo "Address should not be empty";
    }
} else {
    echo "Username should not be empty";
}