VB - Click Same Button Twice - vb.net

Question

Im new to VB and have been searching the internet for answer.
Im trying to create a launcher that allows you to simply locate your exe and run the exe.
Problem is that i can't figure out how to have those 2 actions to happen with just 1 button.
e.g: Click " Play " will open a folder where you have to locate your exe, once its located the folder closes and then when you press " Play " again, it launches the allready located exe.
What i got so far is:
Private Property TextBox As String
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
OpenFileDialog1.ShowDialog()
TextBox = OpenFileDialog1.FileName("/Wow.exe")
Process.Start(TextBox)
End Sub
End Class
It works " almost " as i want it to.
As of now, when i press the " Play " it simply opens a folder where i can select the .exe and then when the folder closes, it opens the .exe automatically. When i press the " Play button again it repeats the process. It even launches the .exe if i press the "exit button (top right)" on the folder.
Could it be possible to make it come with an error if its not the correct file that has been selected ??
Hope you can help me.
Thanks in advance.

Answer 1

How about something like this:
Private filePath As String = String.Empty
Private Sub PlayButton_Click(sender As System.Object, e As System.EventArgs) Handles PlayButton.Click
Try
If filePath.Length = 0 Then
Dim diagResult As DialogResult = OpenFileDialog1.ShowDialog()
If diagResult = Windows.Forms.DialogResult.OK Then
filePath = OpenFileDialog1.FileName
If filePath.ToUpper.EndsWith("WOW.EXE") Then
Process.Start(filePath)
Else
MessageBox.Show("Wrong file selected!")
filePath = String.Empty
End If
End If
Else
Process.Start(filePath)
End If
Catch ex As Exception
MessageBox.Show(String.Concat("An error occurred in the play button click:", ex.Message))
End Try
End Sub