Постоянная ошибка в eclipse(ADT): cannot be resolved or is not a field

package com.example.probnik;
 
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.RelativeLayout;
import android.widget.TextView;
 
 
public class MainActivity extends Activity {
 
    public TextView Hello;
     
    public RelativeLayout relativelayout;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Hello = (TextView) findViewById(R.id.textView1);
    }
public void hello_click(View v){
     TextView Hello=(TextView)findViewById(R.id.textView1);
      relativelayout =(RelativeLayout) findViewById(R.id.relativelayout);
     Hello = (TextView) findViewById(R.id.textView1);
     
 }
 
public void buttonClickRed(View v){
    
    Hello.setText(R.string.red);
    relativelayout.setBackgroundResource(R.id.red_color); // <---
}
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}