make an array of dictionary in plist swift -

i trying create plist this... using code objective-c translated swift... unfortunately array empty remains

what wrong? in advance!

 <plist version="1.0">     <array>         <dict>              <key>uscita_ore</key>             <string>18</string>         </dict>         <dict>              <key>uscita_ore</key>             <string>17</string>         </dict> </array> </plist>  var paths = nssearchpathfordirectoriesindomains(nssearchpathdirectory.documentdirectory, nssearchpathdomainmask.userdomainmask, true) nsarray             var documentsdirectory:anyobject = paths[0]             var path = documentsdirectory.stringbyappendingpathcomponent("orari_marcate.plist")             var filemanager = nsfilemanager.defaultmanager()             var fileexists:bool = filemanager.fileexistsatpath(path)             var lista_marcate : nsmutabledictionary?             var marcate2 :nsmutablearray?              if fileexists == false {                  marcate2 = nsmutablearray (capacity: 0)              } else  {                  marcate2 = nsmutablearray(contentsoffile: path)             }              lista_marcate?.setvalue("\(campo_ora_fine.text)", forkey: "campo_ora_fine")             lista_marcate?.setvalue("\(campo_min_fine.text)", forkey: "campo_min_fine")             lista_marcate?.setvalue("\(fine_ora)", forkey: "fine_ora")             lista_marcate?.setvalue("\(fine_min)", forkey: "fine_min")               marcate2?.addobject(lista_marcate!)              marcate2?.writetofile(path, atomically: true)               println(path)