Min POST-form virker ikke

PHP kode 

 <?php
 if($_POST['submit']){
 mysql_query("INSERT INTO Notes set CompanyID = '$Company[ID]', UserID = '$Profile[ID]', NoteText = '$_POST[NewNoteText]'");
 echo "<meta http-equiv='refresh' content='0;url=?Side=OpretAnnonce'>";
 }
 ?>

HTML kode 

 <form name="form1" method="post" action="" class="post_message">
 <input type="text" value="Skriv ny note" name="NewNoteText" onfocus="if(!this._haschanged){this.value=''};this._haschanged=true;">
 <input type="submit" name="submit" class="btn_post_message" value=""/>
 </form>