Question

I am getting an error when loading the page without any GET parameters (eg.: /login.php), here is the error I get:

 ( ! ) Notice: Undefined index: err in          C:\wamp\www\GestionImagesPublicitesAvis\login.php on line 57
    Call Stack
    #   Time    Memory  Function    Location
     1  0.0005  144120  {main}( )   ..\login.php:0

And here is the code snippet from line 41 to line 58:

    <input class=
            <?php if(!empty($err))
                {
                    if($err == "up")
                    {
                        echo "\"InputError\"";
                    }
                    else
                    {
                        echo "\" \"";
                    }
                }
                else
                {
                    echo "\" \"";
                } ?> 
            type="text" name="username" onclick="this.value='';" onblur="this.value=!this.value?'login...':this.value;" value=<?php if (($_GET['err'] == 'up')&& (isset($_GET['u']))){echo ("\"" . $_GET['u'] . "\"");}else{ echo "\"login...\"";} ?> id="username"/>
            <input class=<?php if($err=="up"){echo "\"InputError\"";}else{echo "\"\"";}?> type="password" name="password" onclick="this.value='';" onblur="this.value=!this.value?'motdepasse':this.value;" value="motdepasse" id="password"/>

$err is defined earlier in the page (line 15):`

<?php 
            $err;
                if (isset($_GET['err']))
                {
                    switch ($_GET['err'])
                    {
                    case "up":
                        $err = "up";
                        echo "<p>Error #156</p>";
                        break;
                    }
                }
                else
                {
                    $err=null;
                    echo "<p>Error #157</p>";
                }
            ?>

Answer 1

On the top of the page (second code example) you only make sure $err is set and not $_GET['err']. Later on in line 57 (first code example), however, you again just use $_GET['err'].

Your error should be fixed, if you refer to $err in the code, after initializing it.

So your line 57 should similar to this:

type = "text" name="username" onclick="this.value='';" onblur="this.value=!this.value?'login...':this.value;" value=<?php if (($err == 'up')&& (isset($_GET['u']))){echo ("\"" . $_GET['u'] . "\"");}else{ echo "\"login...\"";} ?> id="username"/>