javascript 从applet 取值问题请教

执行applet，包括以下代码：
TO中：
private EEPTempData rfIDData = null;
public EEPTempData getRfIDData() {
  return rfIDData;
}
public void setRfIDData(EEPTempData rfIDData) {
  this.rfIDData = rfIDData;
}

private EEPTempEndorsementData rfIDEndorsementData[] = null;
public EEPTempEndorsementData[] getRfIDEndorsementData() {
  return rfIDEndorsementData;
}
public void setRfIDEndorsementData(EEPTempEndorsementData rfIDEndorsementData[]) {
  this.rfIDEndorsementData = rfIDEndorsementData;
}

run 方法中：

EEPTempData tempData = new EEPTempData();
tempData.setNatCd("CHN");
this.applet.setRfIDData(tempData);

EEPTempEndorsementData tempEndosements[] = new EEPTempEndorsementData[2];
EEPTempEndorsementData endorsementData1 = new EEPTempEndorsementData();
EEPTempEndorsementData endorsementData2 = new EEPTempEndorsementData();
endorsementData1.setNatCd("CHN");
endorsementData2.setNatCd("CHN");
tempEndosements[0] = endorsementData1;
tempEndosements[1] = endorsementData2;
this.applet.setRfIDEndorsementData(tempEndosements);


在jsp页面通过javascrit 取值：
可以取到单个实例的值：
alert(document.applets['EEPOCRApplet'].getRfIDData().getNatCd()); 显示 CHN   
但是取不到实例数组的值：
document.applets['EEPOCRApplet'].getRfIDEndorsementData()[0] 出错。

alert(typeof(document.applets['EEPOCRApplet'].getRfIDEndorsementData())); 显示 unknown   
请大虾们帮帮忙，谢谢