How to Retrieve Deleted table's Data ?..

Question

 Dear Friends ,

                      I am new to Oracle database systems. I have  done  huge mistake two days ago.when i try to move the Particular Month (Jan) data  to 

     JanBackup Table from the bulk backup Table.Wrongly Jan moth data deleted. 

                      That was highly valuable data. I desperately resume those data...

          Version is : Oracle 8i      

                     I f possible to anyone  help me out..

                           Thanks  In     Advance 

                             

 

                                                                                                                                                                                             Karthik.k