Data transfer from excel to sqlserver using linked server

Question

Dear all,
   i created link between sql server and excel file using linked server .the data is transfered from excel to sql server .thats working fine.Consider previously 3 rows are been in excel file.

  when i insert a new row in sqlserver what happens the new row is added and also the previous 3 rows is again repeated like 3+3 +1 (new row).how to avoid this repeated row.below is the query i used.

insert into queryexcel...Sheet1$(PersonNumber,LastName,Firstname,ThirdName,CardNumber)select * from dbo.tbl_emp1


Please give me some idea.

Thanks,
Dhilip