Exception in thread "main" how to solve java.lang.ArrayIndexOutOfBoundsException: 0

1.i am new to java so im a noob but im trying to make this chat server and client the server so far will run but the client wont and returns the error in the title please help and try and keep it noob friendly :)

import java.net.*;
import java.io.*;
import java.awt.*;

@SuppressWarnings("serial")
class chatClient extends Frame implements Runnable
{
Socket soc;    
TextField tf;
TextArea ta;
Button btnSend,btnClose;
String sendTo;
String LoginName;
Thread t=null;
DataOutputStream dout;
DataInputStream din;
chatClient(String LoginName,String chatwith) throws Exception
{
    super(LoginName);
    this.LoginName=LoginName;
    sendTo=chatwith;
    tf=new TextField(50);
    ta=new TextArea(50,50);
    btnSend=new Button("Send");
    btnClose=new Button("Close");
    soc=new Socket("127.0.0.1",5211);

    din=new DataInputStream(soc.getInputStream()); 
    dout=new DataOutputStream(soc.getOutputStream());        
    dout.writeUTF(LoginName);

    t=new Thread(this);
    t.start();

}
@SuppressWarnings("deprecation")
void setup()
{
    setSize(600,400);
    setLayout(new GridLayout(2,1));

    add(ta);
    Panel p=new Panel();

    p.add(tf);
    p.add(btnSend);
    p.add(btnClose);
    add(p);
    show();        
}
@SuppressWarnings("deprecation")
public boolean action(Event e,Object o)
{
    if(e.arg.equals("Send"))
    {
        try
        {
            dout.writeUTF(sendTo + " "  + "DATA" + " " + tf.getText().toString());            
            ta.append("\n" + LoginName + " Says:" + tf.getText().toString());    
            tf.setText("");
        }
        catch(Exception ex)
        {
        }    
    }
    else if(e.arg.equals("Close"))
    {
        try
        {
            dout.writeUTF(LoginName + " LOGOUT");
            System.exit(1);
        }
        catch(Exception ex)
        {
        }

    }

    return super.action(e,o);
}
public static void main(String[] args) throws Exception
{
    chatClient Client=new chatClient(args[0], args[1]);
    Client.setup();                
}    
public void run()
{        
    while(true)
    {
        try
        {
            ta.append( "\n" + sendTo + " Says :" + din.readUTF());

        }
        catch(Exception ex)
        {
            ex.printStackTrace();
        }
    }
}
}