title: My app keeps saying "unfortunately it has stopped". I don't know why it is crashing
body: <p>In my activity, the user can input numbers into a EditViews, then click a button to calculate, the result is displayed below. However, if a user edits an EditView, clicks calculate, then goes back to edit an EditView again, the app crashes when the user clicks calculate to recalculate a new total.</p>
  
  <p>Full log:</p>
  
  <pre><code>06-24 09:14:06.025 2618-2637/washingtondeli.groupboxlunchesestimateandordering D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
  
                                                                                                   [ 06-24 09:14:06.035  2618: 2618 D/         ]
                                                                                                   HostConnection::get() New Host Connection established 0xaac28fe0, tid 2618
  06-24 09:14:06.109 2618-2637/washingtondeli.groupboxlunchesestimateandordering I/OpenGLRenderer: Initialized EGL, version 1.4
  06-24 09:14:10.220 2618-2637/washingtondeli.groupboxlunchesestimateandordering E/Surface: getSlotFromBufferLocked: unknown buffer: 0xae6cc2a0
  06-24 09:14:10.226 2618-2637/washingtondeli.groupboxlunchesestimateandordering D/OpenGLRenderer: endAllStagingAnimators on 0xb2a8d580 (RippleDrawable) with handle 0xae452850
  06-24 09:14:13.718 2618-2618/washingtondeli.groupboxlunchesestimateandordering W/ViewRootImpl: Cancelling event due to no window focus: MotionEvent { action=ACTION_CANCEL, actionButton=0, id[0]=0, x[0]=304.2444, y[0]=1010.4492, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=20361, downTime=16521, deviceId=0, source=0x1002 }
  06-24 09:14:13.718 2618-2618/washingtondeli.groupboxlunchesestimateandordering W/ViewRootImpl: Cancelling event due to no window focus: MotionEvent { action=ACTION_CANCEL, actionButton=0, id[0]=0, x[0]=304.2444, y[0]=1010.4492, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=20361, downTime=16521, deviceId=0, source=0x1002 }
  06-24 09:14:13.718 2618-2618/washingtondeli.groupboxlunchesestimateandordering W/ViewRootImpl: Cancelling event due to no window focus: MotionEvent { action=ACTION_CANCEL, actionButton=0, id[0]=0, x[0]=304.2444, y[0]=1010.4492, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=20361, downTime=16521, deviceId=0, source=0x1002 }
  06-24 09:14:13.718 2618-2618/washingtondeli.groupboxlunchesestimateandordering W/ViewRootImpl: Cancelling event due to no window focus: MotionEvent { action=ACTION_CANCEL, actionButton=0, id[0]=0, x[0]=304.2444, y[0]=1010.4492, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=20361, downTime=16521, deviceId=0, source=0x1002 }
  06-24 09:14:37.797 2618-2618/washingtondeli.groupboxlunchesestimateandordering D/AndroidRuntime: Shutting down VM
  
  
                                                                                                   --------- beginning of crash
  06-24 09:14:37.797 2618-2618/washingtondeli.groupboxlunchesestimateandordering E/AndroidRuntime: FATAL EXCEPTION: main
                                                                                                   Process: washingtondeli.groupboxlunchesestimateandordering, PID: 2618
                                                                                                   java.lang.NumberFormatException: Invalid int: "$19.00"
                                                                                                       at java.lang.Integer.invalidInt(Integer.java:138)
                                                                                                       at java.lang.Integer.parse(Integer.java:410)
                                                                                                       at java.lang.Integer.parseInt(Integer.java:367)
                                                                                                       at java.lang.Integer.parseInt(Integer.java:334)
                                                                                                       at washingtondeli.groupboxlunchesestimateandordering.CapitolhillActivity.calculate2(CapitolhillActivity.java:165)
                                                                                                       at washingtondeli.groupboxlunchesestimateandordering.CapitolhillActivity$2.onClick(CapitolhillActivity.java:131)
                                                                                                       at android.view.View.performClick(View.java:5198)
                                                                                                       at android.view.View$PerformClick.run(View.java:21147)
                                                                                                       at android.os.Handler.handleCallback(Handler.java:739)
                                                                                                       at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                                       at android.os.Looper.loop(Looper.java:148)
                                                                                                       at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                                                       at java.lang.reflect.Method.invoke(Native Method)
                                                                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
  </code></pre>