Turn a single partylist field into multiple

Is there a way to transform a partylist field like Customer in a Campaign Response to allow for multiple Contacts/Accounts/Leads?

Although unsupported, I now from Jian Wang that some attr开发者_开发技巧ibutes of the lookup can be modified in the onload() event like this:

crmForm.all.customer.setAttribute("lookuptypes", "1,2");

Is there a similiar attribute that would turn this into a field that allows multiple participants like the To field in an e-mail?

Thank you

I finally found an easy (though unsupported) way of doing this. It doesn't require Javascript code, by the way. I just exported the entity CampaignResponse and edited the XML. Then searched the attribute (Customer) and element LookupStyle

<attribute PhysicalName="Customer">
...
<LookupStyle>single</LookupStyle>
...
</attribute>

Changed the value to multi

<attribute PhysicalName="Customer">
...
<LookupStyle>multi</LookupStyle>
...
</attribute>

Reimported, and it worked!