Java Applet drawing Board

Import java.awt.*;
Import javax.swing.*;
Import java.awt.event.*;
public class Huatu implements mousemotionlistener,actionlistener{
static final int r=3;
static int ox, OY;
static int flag=1;
public static void Main (String arg[]) {
JFrame f=new JFrame ("Paint");
Container P=f.getcontentpane ();
P.setlayout (New FlowLayout ());
JButton jButton1 = new JButton ("Red");
JButton jButton2 = new JButton ("Black");
JButton JButton3 = new JButton ("Exit");
Graphics G.setcolor (New Color (255,0,0));
Buttonevent arg=new buttonevent (ARG);
Jbutton1.addactionlistener (New Huatu ());
Jbutton2.addactionlistener (New Huatu ());
Jbutton3.addactionlistener (New Huatu ());
P.addmousemotionlistener (New Huatu ());
P.add (JButton1);
P.add (JButton2);
P.add (JButton3);
F.setsize (200,200);
F.show ();
}
public void actionperformed (ActionEvent e) {
if (E.getactioncommand (). Equals ("Red")) {
flag=1;
}
else if (E.getactioncommand (). Equals ("Black")) {
flag=2;
}
else if (E.getactioncommand (). Equals ("Exit"))
System.exit (0);
}
public void mousedragged (MouseEvent e) {
Container c= (Container) E.getsource ();
Graphics G=c.getgraphics ();
if (ox>=0) {
if (flag==1) {
G.setcolor (New Color (168,0,255));
G.drawline (Ox,oy,e.getx (), e.gety ());}
Else
{G.setcolor (new Color (0,0,0));
G.drawline (Ox,oy,e.getx (), e.gety ());}
}
Ox=e.getx (); Oy=e.gety ();
}
public void mousemoved (MouseEvent e) {
Ox=-1;oy=-1;
}
}