Text Validation

import java.awt.event.*;
import java.awt.*;
class TextValid extends KeyAdapter
{
public void keyTyped(KeyEvent e)
{
char ch=e.getKeyChar();
if((ch >= 'a' && ch <='z')||(ch >='A' && ch <='Z'))
{
}
else
{
Toolkit.getDefaultToolkit().beep();
e.consume();
}
}
}