Linear Search of an Array

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class LinearSearch extends JApplet implements ActionListener 
     {
     JLabel enterLabel, resultLabel;
     JTextField enter, result;
     int a[];
    
     public void init()
         {
         Container c = getContentPane();
         c.setLayout( new FlowLayout() );
        
         enterLabel = new JLabel( "Enter integer search key" );
         c.add( enterLabel );
        
         enter = new JTextField( 10 );
         enter.addActionListener( this );
         c.add( enter );
        
         resultLabel = new JLabel( "Result" );
         c.add( resultLabel );
        
         result = new JTextField( 20 );
         result.setEditable( false );
         c.add( result );
        
         // create array and populate with even integers 0 to 198
         a = new int[ 100 ];
        
         for ( int i = 0; i < a.length; i++ )
         a[ i ] = 2 * i;
        
     }
    
     // Search "array" for the specified "key" value
     public int linearSearch( int array[], int key )
         {
         for ( int n = 0; n < a.length; n++ )
         if ( array[ n ] == key )
         return n;
        
         return -1;
     }
    
     public void actionPerformed( ActionEvent e )
         {
         String searchKey = e.getActionCommand();
        
         // Array a is passed to linearSearch even though it
         // is an instance variable. Normally an array will
         // be passed to a method for searching.
         int element = linearSearch( a, Integer.parseInt( searchKey ) );
        
         if ( element != -1 )
         result.setText( "Found value in element " + element );
         else
         result.setText( "Value not found" );
     }
}