Someone

<script type="text/javascript">
function addlink()
{
  var ele = document.getElementById('imdblinks');
  if (!ele) return;

  ele.innerHTML += "<p>IMDB Link: &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<input type='text' name='imdblink[]' size='25' /> &nbsp;  Poster Image Name: <input type='text' name='postername[]' size='25' /></p>";
}
</script>

<div id="wrap" style="margin-left: 20px;">
<p>Add a movie:</p>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>?page=add" method='post' name='addform'>
<fieldset id="imdblinks">

<p>IMDB Link: &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<input type='text' name='imdblink[]' size='25' /> &nbsp;  Poster Image Name: <input type='text' name='postername[]' size='25' /></p>

</fieldset>

<fieldset>
<input type="hidden" value="0" id="nextvalue" />
<p><input type="button" name="addanother" value="Add Another/></p>
<p><input type="submit" name="addmovie" value="Add Movie" /></p>
</fieldset>

</form>

</div>