php script just inserts one row. there is an auto increment id

You have a error here -> $result_verify_mobileno = mysqli_query($dbc, $query_verify_mobileno);

What's $dbc ?

Post out database_connection.php, too ?

this is my database_connection.php

<?php

/*Define constant to connect to database */
DEFINE('DATABASE_USER', 'xxxxxxxx');
DEFINE('DATABASE_PASSWORD', 'xxxxxxxx');
DEFINE('DATABASE_HOST', 'localhost');
DEFINE('DATABASE_NAME', 'xxxxxxxxx');
/*Default time zone ,to be able to send mail */
date_default_timezone_set('Asia/Calcutta');




//This is the address that will appear coming from ( Sender )
define('EMAIL', 'rahul19dj@gmail.com');

/*Define the root url where the script will be found such as http://website.com or http://website.com/Folder/ */
DEFINE('WEBSITE_URL', 'xxxxxxxxxxxxx');


// Make the connection:
$dbc = @mysqli_connect(DATABASE_HOST, DATABASE_USER, DATABASE_PASSWORD,DATABASE_NAME);

if (!$dbc) {
    trigger_error('Could not connect to MySQL: ' . mysqli_connect_error());
}

?>

it seems like everything is ok.

What error message did you get ?

If the fname is same like the one in database it gives me error Query Failed and You could not be registered due to a system error. We apologize for any inconvenience.

Besides dealing with your current issue with the query failing (more than likely due to $_POST['mobileno']), the value $_POST['checkbox'] is an array and needs to be handled as such.  This should work.

if (isset($_POST['checkbox'])){
$mumbai=(in_array("mumbai",$_POST['checkbox']) ? 1 : 0);
$pune=(in_array("pune",$_POST['checkbox']) ? 1 : 0);
$banglore=(in_array("banglore",$_POST['checkbox']) ? 1 : 0);
$mysore=(in_array(1,$_POST['checkbox']) ? 1 : 0);	
}

If the fname is same like the one in database it gives me error Query Failed and You could not be registered due to a system error. We apologize for any inconvenience.

But.... this one is not true, right ?

it should not happen, as I havent given any such condition

hey jazzman1 thanks for the last help for the checkbox.

I was scratching my head for the same too.

Thanks, now just that fname mystery

Ok, I think that you have an logically error.

You use in the same if statement mysqli_num_rows and after that inside in this statement you called mysqli_affected_rows.

There is nothing unusual 

Why did you use mysqli_num_rows and mysqli_affected_rows ?

That is used for 2 reasons.

1. if no one has registered with that mobile number then do the insert

2. if the insert gets complete then send an email to the registered user

hey how do I add a prefix to the mobileno and also limit them only for 10 digit and give error if more than 10 digit

IF you echo $query_insert_user by adding this line below setting the variable, does it show expected variables for each field?

echo "$query_insert_user";

By the way, you don't need all that extra markup in there.

$query_insert_user = "INSERT INTO userdtls (mobileno,pass,fname,lname,email,MUM,PUN,BNG,MYS) VALUES ('$mobile','$password','$fname','$lname','$email','$mumbai','$pune','$banglore','$mysore')";

And if you haven't fixed the "checkbox" section with this code, then all those variables may not be getting set, also causing the query to fail.  Echo the query to see if all values are passed to the query.

if (isset($_POST['checkbox'])){
$mumbai=(in_array("mumbai",$_POST['checkbox']) ? 1 : 0);
$pune=(in_array("pune",$_POST['checkbox']) ? 1 : 0);
$banglore=(in_array("banglore",$_POST['checkbox']) ? 1 : 0);
$mysore=(in_array(1,$_POST['checkbox']) ? 1 : 0);	
}

hey i solved tht problem thanks a tonn for your help