google apps script - There doesn't seem to be a folder object -

ok, officially driving me nuts. getting error "typeerror: cannot find function addfile in object jobsheetjune2015." code. have same code elsewhere similar except creating folder , adding file, no problems. cannot seem figure out why folder not folder object can accept addfile(). log shows folders folderiterator, expected. log shows name of folder jobsheetjune2015, not sure if should case, thought should show folder, in other part of code shows folder name well, maybe fine.

i'm missing something, , have run out of ideas. grateful , insight.

if (driveapp.getfoldersbyname('jobsheet' + year).hasnext() == true) {     if (driveapp.getfoldersbyname('jobsheet' + months + year).hasnext() == true) {    var folders = driveapp.getfoldersbyname('jobsheet' + months + year);    var folder = folders.next();    var file = driveapp.getfilesbyname(newspreadsheetname).next();    folder.addfile(file);      } } 

you may kick this, looks have typo. need capitalize "f" in folder.addfile(file). should folder.addfile(file);

whenever see error "typeerror: cannot find function _____ in object _____." means trying call method not exist in object referencing. means either typo or object trying manipulate different type expected. keep tidbit in pocket next time need debug.