I'm trying to create a button in the application from one activity to another. The document resource/values/strings.xml created for this ID: <string name="button1name"> CID </ string> But the document GurovPictures.java (this is my main activity) when I insert a line: Button but1 = (Button) findViewById (R.id.button1); This "button1" does not become blue like "editText1". Do you happen to know how to fix it? Just the internet no entries found.