title: Invalid float after new Decimal Format
body: <p>User want to raise temperature from EditText "set_temp". 
  Currtemp is global string means current temperature</p>
  
  <pre><code>float temp = Float.parseFloat(set_temp.getText().toString());
  temp-=0.1;
  currTemp=new DecimalFormat("#0.0").format(temp);
  set_temp.setText(currTemp);
  </code></pre>
  
  <p>After this i have an error in logcat </p>
  
  <pre><code>FATAL EXCEPTION: main
  Process: ru.unn.caminlab, PID: 7835
  java.lang.NumberFormatException: Invalid float: "49,9"
  </code></pre>
  
  <p>// but why?</p>