Button["Esporta", SetSystemOptions["CacheOptions" -> {"Symbolic" -> False}];
 SelectionMove[ButtonNotebook[], All, GeneratedCell];
 NotebookDelete[ButtonNotebook[]]; Module[{},
  p := Plot[Sin[x], {x, 0, 2 Pi}];
  Export[SystemDialogInput["FileSave", "grafico.jpg"], p, ImageResolution -> 200];
 ], Method -> "Queued"]