form action - validator problem

Line 27, Column 5: required attribute "ACTION" not specified.
<form>
The attribute given above is required for an element that you've used, but you have omitted it. For instance, in most HTML and XHTML document types the "type" attribute is required on the "script" element and the "alt" attribute is required for the "img" element.
Typical values for type are type="text/css" for <style> and type="text/javascript" for <script>.

<form action="mailer.php" method="post">
<input maxlength="80" type="text"size="12" value="Meno" name="meno" onClick="this.value='';"/><br />
<input maxlength="80" type="text" size="12" value="Váš e-mail" name="email" onClick="this.value='';"/><br />
<textarea cols="10" rows="3" name="sprava"></textarea><br>
<input type="submit" alt="Odošli">
</form>