Fatal error: Uncaught Error: Call to a member function bindParam() on string
in C:xampphtdocssignregister.php:20 Stack trace: #0 {main} thrown in
C:xampphtdocssignregister.php on line 20

<?php
include('connection.php');
$form = $_POST;
$username = $form['username'];
$password = $form['password'];
$repass = $form['repass'];
$email = $form['email'];
$date = $form['date'];
$month = $form['month'];
$year = $form['year'];
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
echo "Invalid email please type a valid one";
}
else{
if($username !='' && $password !='' && $repass!='' && $email !='' &&
$date!='' && $month !='' && $year !='')
{
if($password == $repass)
{
$query = "SELECT * FROM users where email = :email AND username =
:username";
$query->bindParam(':username',$username);
$query->bindParam(':email',$email);
$count1 = $query->rowCount();
if($count> 0)
{
    echo "soryy the email you are trying to register is already
registered!";
}
else{

$insert = $connection->prepare("INSERT INTO users
(username,password,email,date,month,year)  values (:username, :password,
:email, :date, :month, :year)");
$insert->bindParam(':username',$username);
$insert->bindParam(':password',$password);
$insert->bindParam(':email',$email);
$insert->bindParam(':date',$date);
$insert->bindParam(':month',$month);
$insert->bindParam(':year',$year);
$out = $insert->execute();
if(isset($out)){
    echo "thankyou you have sucessfully registered";
}
else{
    echo " sorry some error occured please try again!";
}
}
}
else{
echo " passwords do not match";
die();
}
}
else{
echo " you have not filled the registration form completely so please it";
}
}
?>