I am trying to make this expression in textbox1 in the report header "= IsNull(Sum(IsNull(Fields.part1,0) - IsNull(Fields.part1,0) + IsNull(Fields.part3,0)),0)" where part1 ,part2 and part3 come from datasource1
And I have in a table the detailed section, its datasource is datasource1
this make result in table duplicated more times
any suggestion for setting textbox1 with different way ??