alert user of error/missing data in form?

[helraizer1]

Hi folks, I have this site and idea

http://www.helraizer.co.uk/mychatbox/

at the moment I'm using javascript to alert the user if they haven't entered a username or message but all this does is popup an alert message and return false. However, if their browser does not support javascript (javascript is turned off) then it just won't send and will give them no reason why.

How would I get it so that, using php, if the submit button is pressed and either the username is less than 3 characters and/or the comment field is less than 5 characters then above the image (on the site page) a list of errors would appear.

So if nothing was wrong it shows no errors but if the user name was less than 3 characters and comment <5 it'd appear
"Error!
-Your username is too short, please enter a user name between 3 and 10 characters.
-Your comment is too short, please enter a comment between 5 and 75 characters." (or similar)

How would I do this?

I know this is a "help" forum not a "do it for me forum" but if you guys can give me a baseline for this problem, to work with from there I can probably get it from there. =)

Thanks,
Sam

[eragon]

PHP can not make an alert box, but it can print an error to the page.

are your boxes submitting to an input page, if so i would suggest looking at the php function strlen(). pass both inputs through this, and it its less than what is expected die() your error.

example:

[PHP]$str1 = "Apple";
$str2 = "Banana";

$len1 = strlen($str1);
$len2 = strlen($str2);

if($len1 < 6) {
die('Apple is less than 5 chars.');
}

if($len2 < 4) {
die('Banana is less than 4 chars.');
}[/PHP]

so if you want to figure it out there you go, if not ask and ill work it into your code.

[helraizer1]

PHP can not make an alert box, but it can print an error to the page.

are your boxes submitting to an input page, if so i would suggest looking at the php function strlen(). pass both inputs through this, and it its less than what is expected die() your error.

example:

[PHP]$str1 = "Apple";
$str2 = "Banana";

$len1 = strlen($str1);
$len2 = strlen($str2);

if($len1 < 6) {
die('Apple is less than 5 chars.');
}

if($len2 < 4) {
die('Banana is less than 4 chars.');
}[/PHP]

so if you want to figure it out there you go, if not ask and ill work it into your code.

Hey Eragon, thanks for that. I worked out a solution for the problem =)

This is the php code I used, it seems to work with out any bugs so far, could you let me know if it's good enough or if there is any way it could be improved?

<?php
 
unset($errors);
 
include("linesfile.php5");
            $filename = "data.line";
            set_magic_quotes_runtime(0);
 
            if($_POST['submit'] && strlen($_POST['input']) < 5) {    
                $errors[] .= _NO_5;
                            }
            if($_POST['submit'] && strlen($_POST['username']) < 3) {
                $errors[] .= _NO_2;
                            }
 
?>
              <div class="ddgb_entrybox">
        <table width="100%" border="0" cellspacing="8" cellpadding="0">
        <tr>
        <td width="42%" align="right" valign="top"></td>
        <td align="left" valign="top">
<?php  
 
if(isset($_POST['submit']) && $errors[0] != null) {
     echo "<h2>" . _ERROR . "</h2><ul>";
        foreach ($errors as $f) {
            echo "<li>" . $f . "</li>";
        }
        echo "</ul>";
}    
 
            elseif($_POST['submit']) {
            // grab the inputted text
            $text = htmlspecialchars(stripcslashes($_POST['input'] . "\n"));
            $username = htmlspecialchars(stripslashes($_POST['username']));
            $color = $_POST['color'];
            $font = $_POST['font'];
            $ip = $_SERVER['REMOTE_ADDR'] . "\n";
            $_SESSION['username'] = $username;
            $_SESSION['color'] = $color;
                    $dirty = array(); // dirty words here, I removed them to keep this thread clean
 
                        foreach($dirty AS $bad_word){
                        $text = preg_replace("/$bad_word/i","****", $text);
                        }   
 
 
 
 
 
 
            $data[] ="\n". htmlspecialchars_decode(substr($username,0,10));
            $data[] =trim($color);
            $data[] =trim($font);
            $data[] =htmlspecialchars_decode(trim(substr($text,0,75)));
 
 
            $datafile = new DataFile($filename);
            if(!$datafile->writeNewLine($data)) die("Error writing to file");
 
 
 
 
 
}
 
          ?>
 

_ERROR
_NO_5
_NO_2
have all been defined in a different document.

Sam