email recepient field autocomplete=off -> how to get rid of it

Hey!

I would like to have the autocomplete option turned ON on the email field when sending emails from the CRM.
At the moment the field has autocomplete=off parameter on it. Where/how would be the best/easiest way to get rid of that parameter in order to get the normal autocomplete list when entering an email recepient.

There seems to be some JS also attached to it, as whenever I manally remove that part attribute from the input field (just for testing), it pops right back up when element is in focus.

below is the HTML code of the element

<div class="ac_autocomplete yui-ac">                                   <span id="move_to_bcc_span1" style="padding-left:9px"><a href="#" onclick="SE.composeLayout.moveToBCC('move_to_bcc','1');">Verschieben zu Bcc</a></span><br>         &nbsp;&nbsp;<input class="ac_input yui-ac-input" size="96" id="addressTO1" title="An" name="addressTO1" onkeyup="SE.composeLayout.showAddressDetails(this);" autocomplete="off" type="text">         <span class="rolloverEmail"> <a id="MoreaddressTO1" href="#" style="display: none;">+<span id="DetailaddressTO1">&nbsp;</span></a> </span>         <div class="ac_container yui-ac-container" id="addressToAC1"><div class="yui-ac-content" style="display: none;"><div class="yui-ac-hd" style="display: none;"></div><div class="yui-ac-bd"><ul><li style="display: none;"></li><li style="display: none;"></li><li style="display: none;"></li><li style="display: none;"></li><li style="display: none;"></li><li style="display: none;"></li><li style="display: none;"></li><li style="display: none;"></li><li style="display: none;"></li><li style="display: none;"></li></ul></div><div class="yui-ac-ft" style="display: none;"></div></div></div>        </div>

Thank you for any ideas/help.