Multi Select Look up in form Level in Ax 2012

Multi Select Look Up in Form

public class FormRun extends ObjectRun
{
    SysLookupMultiSelectCtrl       msCtrlCust;
    QueryBuildDataSource           qbds;
    QueryBuildFieldList            qbfl;

} 

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public void init()
{
    Query query = new Query();
    super();

    qbds = query.addDataSource(tableNum(CustTable));
    qbds.fields().dynamic(NoYes::Yes);
    qbfl   =   qbds.fields().addField(fieldNum(CustTable, AccountNum));

    msCtrlCust = SysLookupMultiSelectCtrl::constructWithQuery(element, CustMultiLookUp_AccountNum, query);

}

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void clicked()
{
    container   con;
    int         i;
    str         multiSelectString;
    Args        args;
    container   values = msCtrlCust.get();

    super();

    args = new Args();

    for (i = 1; i <= conLen(values); i++)
    {
        con = conIns(con,1,conPeek(values,i));
    }
    multiSelectString = con2Str(con,',');
    args.parm(multiSelectString);
    new MenuFunction(menuitemDisplayStr(CustMultiLookUpData), MenuItemType::Display).run(args);
}
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