Scriptaculous Autocompleter doesn't work at all in IE7

When I use this code:

function tx_oriconvocatorias_pi1_init(ctrlId, acId, bcampo) {
    document.observe('dom:loaded', function() {
        new Ajax.Autocompleter(ctrlId, acId, 'index.php', {
            parameters: 'eID=ori_convocatorias&bcampo='+bcampo,
            paramName: 'buscarAjax'
        });
    });
}

It works well in all navigators except IE.

In IE8 the resultant ul list is displayed in other place in the screen. In IE7 it displays a rectangle at the right of the field and doesn't display any suggestion when user writes in the field.

The HTML of the field is:

<td>
<input type="text" autocomplete="off" value="开发者_运维问答" id="porgof" name="porgof" size="50">
<div id="porgofAjax" style="display: none;"></div>
<script type="text/javascript">tx_oriconvocatorias_pi1_init('porgof','porgofAjax','porgof')</script>
</td>

Thanks.

No matters. There was a comma at the end of an array in other script.