login_pop.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:id="@+id/UserNameEditText"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:maxLength="20"
        android:digits="0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM_"
        android:hint="User Name"/>
    <EditText
        android:id="@+id/PwdEditText"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:maxLength="20"
        android:password="true"
        android:digits="0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM"
        android:hint="Pwd"/>
</LinearLayout>