Добавление записей в базу данных

<?php
$con=mysqli_connect("localhost","root","","witcher");
 
 
 
if (!$con) {
      die("Connection failed: " . mysqli_connect_error());
}
 
echo "Connected successfully";
 
 
        if(isset($_POST['post']))
        {
            $post_title=$_POST['post_title'];
            $post_cat=$_POST['cat'];
            $post_keywords=$_POST['post_keywords'];
            $post_image=$_FILES['post_image']['name'];
            $post_image_tmp=$_FILES['post_image']['tmp_name'];
            $post_content=$_POST['post_content'];
 
 
            if($post_title=='' OR $post_cat=='null' OR $post_keywords=='' OR $post_image=='' OR $post_content=='' )
            {
                echo "<script>alert('Заполните все поля!')</script>";
                exit();
            }
            else
            {
                move_uploaded_file($post_image_tmp, "news_images/$post_image");
                $insert="INSERT INTO post (category_id,post_title,post_keywords,post_image,post_content)values('$post_cat','$post_title', '$post_keywords','$post_image', '$post_content')";
        
                if (musqli_query($con, $insert))//вот тут ошибка
                {
                 echo "New record created successfully";
                
} else {
      echo "Error: " . $insert . "<br>" . mysqli_error($con);
}mysqli_close($con);
            }
 
 
        }
 
?>