我需要发送值到这个弹出窗口。这是在同一个窗口中打开的。当我尝试与正常的驱动程序。findelement，它的获取错误消息说xpath找不到这是我的代码

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;

public class Homepage_login {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        FirefoxDriver driver = new FirefoxDriver();
        driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);

        //driver.get("http://se.rdmsonline.net/login.aspx");

        driver.get("http://se.rdmsonline.net/");
        driver.findElement(By.xpath("//*[@id='rcmLang_Arrow']")).click();

        driver.findElement(By.xpath("//*[@id='rcmLang_DropDown']/div/ul/li[2]")).click();

        driver.findElement(By.xpath("//*[@id='txtUserName']")).sendKeys(" ");

        driver.findElement(By.xpath("//*[@id='txtPassword']")).sendKeys(" ");

        driver.findElement(By.xpath("//*[@id='btnLogin']")).click();

        driver.findElement(By.xpath("//*[@id='Div1']/div/a")).click();

        driver.findElement(By.xpath("//*[@id='txtUserName']")).sendKeys(" ");

        driver.findElement(By.xpath("//*[@id='txtPassword']")).sendKeys(" ");

        driver.findElement(By.xpath("//*[@id='btnLogin']")).click();

        driver.findElement(By.xpath("//*[@id='rptSec_ctl00_imb']")).click();

        driver.findElement(By.xpath("//*[@id='ctl00_Menu5']")).click();

        driver.findElement(By.xpath("//*[@id='ctl00_cpl1_lnkNewNotification']")).click();

        driver.findElement(By.xpath("//*[@id='ctl00_cplm_dtpDate_dateInput_text']")).sendKeys(" ");


    }

}

这是发送弹出窗口内的控制..有人能帮助我吗？