excel - calling a function to return an array - type mismatch -

i have custom type shown below,

public type typefieldcolumn     icol integer     drow double end type 

i have following sub routine

private sub populateworksheet()  dim wsts worksheet dim clsdata new clsdatabase dim rsts new adodb.recordset dim fields() typefieldcolumn  set wsts = thisworkbook.sheets(somename) set rsts = clsdata.somemethod()  fields = findfactorcolumns(rsts, wsts)  end sub 

which calls function below

private function findfactorcolumns(rsts adodb.recordset, wsts worksheets) typefieldcolumn()  dim integer dim index integer dim factorname string dim flds() typefieldcolumn  redim flds(1 rsts.fields.count - 1)  = 1 rsts.fields.count - 1                           factorname = rsts.fields(i).name     index = mapbloombergindextofactorname(factorname)     if index > 0 factorname = pmap(index).mapname      flds(i).icol = application.worksheetfunction.match(factorname, wsts.range("1:1"), 0)  next   findfactorcolumns = flds   end function 

i run time error of type mismatch on line fields = findfactorcolumns(rsts, wsts) - don't understand why though?

only writing save @rory time, answer.

the type mismatch occurred because wsts, saved single worksheet in populate worksheet sub, declared multiple worksheets in findfactorcolumn function.

because error line occured @ function call, @rory able determine type mismatch looking @ type of variables used in function , comparing them type of same variables when saved in sub.