Copy rows from one table to another, ignoring duplicates
===

Im trying to copy row from table to another using 2 coluom only as the tow table schema is not identical , 
am getting this error

Operand should contain 1 column(s)

Any tips  whats wrong with my statement ?





     Insert table1 ( screenname,list_id )
      Select screenname,list_id
     From table2 As T1
     Where Not Exists    (
                    Select 1
                    From table1 As T2
                    Where 
                   (T2.screenname = T1.screenname,T2.list_id = T1.list_id)
                    )