check if username is registered

benracer

hi,
how can i check if a username entered into a registration form is taken before the submit. a popup would do then transfer the data into the original text field?

i have this

<?
//connection settings

mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("Sorry - We could not connect you to the online shop<br>Please try again later");

$sql="SELECT * FROM $tbl_name WHERE username='$myusername'";
$result=mysql_query($sql);

// Mysql_num_row is counting table row
$count=mysql_num_rows($result);
// If result matched $myusername and $mypassword, table row must be 1 row

if($count==0){
echo "username is not taken";
}
else {
echo "username is taken";
}
?>

this is displayed on the same form/page as the text field

thanks
Ben

halojoy

One good method is to use default $message="";

Then in your FORM Template, you have a display of this variable.
In your re-submitted form eventual error or other info messages
are displayed above or below the form.
Using the value of this $message variable.
Otherwise can an empty string be displayed.

This variable can also be used to indicate if there is an error or if form was correctly filled.
As long as it has not been assigned an error message (it is still empty), then is no error.

// Mysql_num_row is counting table row
$count=mysql_num_rows($result);
// If result matched $myusername and $mypassword, table row must be 1 row

if($count==0){
$message = "username is not taken";
}
else {
$message = "username is taken";
}

Also the POSTed values, like $username
can be re-transfered into form, if the form is needed to be re-displayed:

<input type="text" name="uname" value="<?php echo $username; ?>">

benracer

but how do i get the username from the text field as i dont want it to be submitted as on the form there is also address and email ect.....?

halojoy

??
Explain, please.
My english is not 103%
as my mother language is a completely different language.

Horizon88

You'll probably want to use Javascript to pull the value of the username text field and submit it in a get variable to a popup window that loads the code you've got now to check if the username is taken.

I don't know Javascript well enough to do it, but you'd have a link to say, check.php?user=whatever, which the link would open in a popup window. The check.php file would have your code to check it and output whether or not it is taken.

And out of curiosity, halojoy, what is your native language?