警告:mysqli_error()只需要1个参数，在\Dequit\期中\寄存器中给出0。php在第18行

register.php

register.php

<?php

        if($_POST["password"]==$_POST["cpassword"])
        {
            $con=mysqli_connect("localhost","63327-10162995","123","63327-10162995");


            if(mysqli_connect_errno())
            {
                echo"Failed to connect to MySQL:".mysqli_connect_error();
            }

            $sql="INSERT INTO user(username,password,email,gender,fname,lname)VALUES ('$_POST[username]','$_POST[password]','$_POST[email]','$_POST[gender]','$_POST[fname]','$_POST[lname]')";

            if(!mysqli_query($con,$sql))
            {
                die("Error:".mysqli_error());
            }
            echo"<script type='text/javascript'>
                window.alert('You Have Successfully\ Registered a New Account!');
                document.write('<?php header('Location:http:lab203/63327/63327-10162995/Desktop/Dequit/Midterm/MAct1_Dequit.html');?>')
                </script>";
        mysqli_close($con);

        }
        else
        {
            echo"<script type='text/javascript'>
                window.alert('Password does not match!');
                </script>";

        }           
?>
<?php

        if