C#

private OleDbConnection objConn;<br />
  private OleDbDataAdapter objAdapter = new OleDbDataAdapter();<br />
<br />
  public void DbConnection()<br />
  {<br />
    objConn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;DataSource=Userprogram.mdb");<br />
  }<br />
<br />
  public DataSet SelectSQL(String stable,String sProgramName)<br />
  {<br />
    DataSet ds=new DataSet();<br />
    objConn.Open();<br />
    objCmdSelecte = new OleDbCommand("Select * From Timeway where TW_Program_Name ='" +  sProgramName + "'", objConn);<br />
                <br />
    objAdapter.SelectCommand = objCmdSelecte;<br />
    objAdapter.Fill(ds);<br />
    objConn.Close();<br />
    return ds;<br />
   }<br />
<br />
   public void UpdateSQL(DataSet ds)<br />
   {<br />
     objConn.Open();<br />
     objAdapter.Update(ds);<br />
     objConn.Close();<br />
   }

sqlconn.DbConnection();<br />
   ds = sqlconn.SelectSQL("PS", "Program Ni");<br />
      for (int i = 0; i < 16;i++ )<br />
        {<br />
            ArrayData[i] = ArrayTextbox[i].Text;     //insert modified value<br />
            ds.Tables[0].Rows[0][i + 1] = ArrayData[i];<br />
        }<br />
      ds.AcceptChanges();<br />
      sqlconn.UpdateSQL(ds);

public static string SaveName(string strName)

        [DllImport("MyBloodyDLL.dll", EntryPoint = "SaveName")]
        public static extern string SaveName(string strName);

and when calling the SaveName("string") function later, I get this beautiful exception:
Unable to find an entry point named 'SaveName' in DLL 'MyBloodyDLL.dll