OnClickListener Probleme

package de.schlangguru.stundenplan;


import android.app.Activity;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;


public class Stundenplan extends Activity 
{
    /** Called when the activity is first created. */
    private View tvmo;
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        TextView tvmo = (TextView)findViewById(R.id.tvmo);
        Button button = (Button)findViewById(R.id.mo);
        
        button.setOnClickListener(mo_weg);
    
    }
        
    OnClickListener mo_weg = new OnClickListener() 
    {


		public void onClick(View v)
		{
			tvmo.setVisibility(View.INVISIBLE);
			
		}
    };
}