L'image avatar

<?php
if(isset($_POST['username'], $_POST['password'], $_POST['passverif'], $_POST['email'], $_POST['avatar']) and $_POST['username']!='')
{
	
	if(get_magic_quotes_gpc())
	{
		$_POST['username'] = stripslashes($_POST['username']);
		$_POST['password'] = stripslashes($_POST['password']);
		$_POST['passverif'] = stripslashes($_POST['passverif']);
		$_POST['email'] = stripslashes($_POST['email']);
		$_POST['avatar'] = stripslashes($_POST['avatar']);
	}

  <form action="signup.php" method="post">
        Veuillez remplir ce formulaire pour vous inscrire:<br />
        <div class="center">
            <label for="username">Nom d'utilisateur</label><input type="text" name="username" value="<?php if(isset($_POST['username'])){echo htmlentities($_POST['username'], ENT_QUOTES, 'UTF-8');} ?>" /><br />
            <label for="password">Mot de passe<span class="small">(6 caractères min.)</span></label><input type="password" name="password" /><br />
            <label for="passverif">Mot de passe<span class="small">(vérification)</span></label><input type="password" name="passverif" /><br />
            <label for="email">Email</label><input type="text" name="email" value="<?php if(isset($_POST['email'])){echo htmlentities($_POST['email'], ENT_QUOTES, 'UTF-8');} ?>" /><br />
            <label for="avatar">Image perso<span class="small">(facultatif)</span></label><input type="file" name="avatar" value="<?php if(isset($_POST['avatar'])){echo htmlentities($_POST['avatar'], ENT_QUOTES, 'UTF-8');} ?>" /><br />
            <input type="submit" value="Envoyer" />
		</div>
    </form>