I have an edittext that is 80% of the screen across and a button that should take the remaining 20%, but when text is entered into the box or removed the edittext grows and shrinks.

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

   <LinearLayout
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:orientation="horizontal"
      android:weightSum="100">

      <Button
         android:id="@+id/people_relationFilterB"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_weight="20" />

      <EditText
         android:id="@+id/people_searchBoxET"
         android:text="Search Known"
         android:singleLine="true"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_weight="80" />
   </LinearLayout>

   <ListView
     android:id="@+id/people_listLV"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content" />

</LinearLayout>

```

Any Clues? Thanks!