var internalFieldName = "Department";
var _call_functionCallback = function () {
    if (!CCSLookupUI.Controls[internalFieldName] || CCSLookupUI.Controls[internalFieldName].Ready) {       
      
      functionCallback();       
    } else {
        setTimeout(function () {
            _call_functionCallback();
        }, 10);
    }
};
_call_functionCallback();