title: how to make a textfield numeric by default in lwuit?
body: <p>i tried to make a application which takes the numeric value default.
  i have done coding like this </p>
  
  <pre><code>public void startApp(){
  Display.init(this);
  TextField amt=new TextField();
  Form form=new Form(Test);
  form.addComponent(amt);
  amt.setConstraint(TextField.NUMERIC);
  form.show(); 
  
  }
  </code></pre>
  
  <p>When i setConstraint to numeric. it only accepts numeric value but i need to press the hash key and chage the key entry style to numeric. so how can i make the text field which should only be able to take numeric input by default. 
  thanks in adavance.</p>