[help] droped file's file type[Solved]

ok, what i am trying to do is this

You drag a file into textarea, it checks to see if the file's file type is ".encrypted"
and if it is it will msgbox File is encrypted

if not it will display the files text in textarea.

but i can not get filetype How would i?

[highlight=vbnet]
If IO.Path.GetExtension(TextBox1.Text).ToLower = ".encrypted" Then
MsgBox("File is encrypted!")
End If
[/highlight]