LÜTFEN YARDIM:(OBJECT REFERENCE NOT SET TO AN INSTANCE OF AN OBJECT

	public override DataSet dataGetir(string tabloAd) 
  		{ 
  			string sorgu="SELECT * FROM "; 
  			Dataset1 dataSet1=new Dataset1(); 
  			tabloAdi=tabloAd; 
  			sorgu+=tabloAdi; 
  			adto=new OleDbDataAdapter(sorgu,oledbConn); 
  			ds=new DataSet(); 
  			adto.Fill(ds,tabloAdi); 
  			return ds; 
  		}

public DataSet dataGetir(baglantiSec bS,string tabloAd) 
  		{ 
  			switch(bS) 
  			{ 
  				case baglantiSec.oledbBaglanti: 
  					oledbDatabase dbo=new oledbDatabase(); 
  					dbo.baglan(); 
  					dsF=dbo.dataGetir(tabloAd); 
  					break; 
  				case baglantiSec.sqlBaglanti: 
  					sqlDatabase dbs=new sqlDatabase(); 
  					dbs.baglan(); 
  					dsF=dbs.dataGetir(tabloAd); 
  					break; 
  			} 
  			return dsF; 
  		}

	private void btnListele_Click(object sender, System.EventArgs e) 
  		{ 
  			 
  				string tabloAdi=listBox1.SelectedItem.ToString(); 
  				databaseFactory dF=new databaseFactory(); 
  				DataSet ds=new DataSet(); 
  				if(radioBtnSql.Checked) 
  				{ 
  					dF.baglantiYarat(baglantiSec.sqlBaglanti); 
  					ds=dF.dataGetir(baglantiSec.sqlBaglanti,tabloAdi); 
  					dataGrid1.DataSource=ds.Tables[tabloAdi]; 
  					dataGrid1.SetDataBinding(ds.Tables[tabloAdi],""); 
  				} 
  				else if(radioBtnOledb.Checked) 
  				{ 
  					dF.baglantiYarat(baglantiSec.oledbBaglanti); 
  					ds=dF.dataGetir(baglantiSec.oledbBaglanti,tabloAdi); 
  					dataGrid1.DataSource=ds.Tables[tabloAdi]; 
  					dataGrid1.SetDataBinding(ds.Tables[tabloAdi],""); 
  				} 
  				else 
  				{ 
  					MessageBox.Show(".....YANLIŞ BAĞLANTI SEÇİMİ...."); 
  				} 
  				textBox1.Text=dF.sorguf.ToString(); 
  			 
  		}