New to Java

Can someone help me figure out why my code is not working.
What I am trying to do is make textfields change when I enter numbers and press enter in another text field

Here are the parts that made it stop working:

myufield.addActionListener(handler);

private class TextFieldHandler implements ActionListener {

public void actionPerformed(ActionEvent event)
{
String string = "";
if (event.getSource() == myufield)
string = "test" + event.getActionCommand();
Double string2 = (Double)(Double.parseDouble(string));
myufield.setText(string2 + "");
Double A1 = (Math.PI*((Math.pow((Double.parseDouble(HHfield.getText()) + (Double.parseDouble(rrfield.getText()))),2)) - (Math.pow((Double.parseDouble(rrfield.getText())),2))));
Double A3 = (Double)(2*Math.PI*Double.parseDouble(LLfield.getText()))*(Double.parseDouble(RRfield.getText()) - Double.parseDouble(ttfield.getText()) + (Double.parseDouble(hhfield.getText())));
Double A4 = (Double)(Math.PI*((Math.pow(Math.PI*((Double.parseDouble(hhfield.getText()) + Double.parseDouble(RRfield.getText()) + Double.parseDouble(RRfield.getText()))),2) - Math.pow((Double.parseDouble(RRfield.getText()) + Double.parseDouble(RRfield.getText())),2))));
Double A2 = (Double)(2*Math.PI*((Double.parseDouble(RRfield.getText()) + ((Double.parseDouble(RRfield.getText()) - (3*Double.parseDouble(HHfield.getText())/4))/2)))*Double.parseDouble(LLfield.getText()));
Double L1 = (Double)(Double.parseDouble(LLfield.getText()) + Double.parseDouble(RRfield.getText()));
Double L2 = (Double)(Double.parseDouble(RRfield.getText()) - (3*Double.parseDouble(HHfield.getText())/4));
Double L3 = (Double)(Double.parseDouble(hhfield.getText()));
Double L4 = (Double)(Double.parseDouble(LLfield.getText()) + Double.parseDouble(RRfield.getText()));
Double myua = .000003769911184;
Double myus = .0025132741;
Relfield.setText((L1/(string2*A1)) + 2*(L2/(string2*A2)) + 2*(L3/(string2*A3)) + (L4/(string2*A4)) + "");
Double Relu = (Double)(Double.parseDouble(Relfield.getText()));
Relufield.setText(Relu + "");
}
}

and this is how DOS responds:


C:\Users\zite.1\Desktop\Shapeshift>javac Shapeshift.java
Shapeshift.java:151: <identifier> expected
myufield.addActionListener(handler);
^
Shapeshift.java:151: <identifier> expected
myufield.addActionListener(handler);
^
2 errors

C:\Users\zite.1\Desktop\Shapeshift>