Change Task cannot be assigned to the same person as the previous Catalog Task.

[WilteS]

What do i wrong?

I made a business rule for a change so thats not posible the same user do both task. 

(function executeRule(current, previous /*null when async*/) {

var tsk = new GlideRecord('change_task');

tsk.addQuery('Parent', '==', current.Parent);

tsk.addQuery('sys_id', '!=', current.sys_id);

tsk.query();

if (tsk.next()) {

    if (tsk.assigned_to == current.assigned_to) {

        gs.addErrorMessage('Change Task cannot be assigned to the same person as the previous Catalog Task.');

        current.setAbortAction(true);

    }

}

[WilteS]

the current.parent is empty in the code. but is filled in the table. the table value isn't give in the current.parent