Hello em0s,
About COMBOBOX, i want to add dynamic items, but new entrys must be saved somewere...
what is best way-right method to do that?

store new entrys in a simple file? i must use database?

Simpliest way is to use a text file - where items will be saved.
When loading read the file and fill comboBox (or fill DataTable and bound it to comboBox), then when new insertion (if it is) made, save (you can overwrite the existing file, or add a new (last row) to the text file).

You will need a new namespace (System.Io;)
then..
Create file with File.Creste() method
Read file with StreamReader
Write to file with StreamWriter.

Will it go, or you need some more help.