need a little help with w3c and a form validation

I get this message with a w3c validator:

line 112 column 30 - Fout: end tag for element "form" which is not open

Does anyone know why I get this message?

<form action="action.php" method="post" />

Uw naam:<br />

<input type="text" name="name" size="25" /><br /><br />
  Uw e-mail adres:<br />
<input type="text" name="email" size="25" /><br /><br />
  De naam van uw kennis of vriend:<br />
<input type="text" name="fename" size="25" /><br /><br />
  Het e-mail adres van uw vriend of kennis:<br />
<input name="femail" type="text" size="25" /><br /><br />
  Optional Message:<开发者_开发百科br />
<textarea rows="5" name="recon" cols="45"></textarea><br />
<input type="submit" name="submit" value="Aanbevelen!" />
</form>

You have a self-closing form opening tag. Change:

<form action="action.php" method="post" />

to

<form action="action.php" method="post">