How to open files using dialog box

[vbanswers]

Const forreading = 1, Forwriting = 2
Dim fs, f
 
Private Sub Form_Load()
CommonDialog1.Filter = "All Files(*.*)|*.*|Text files(*.*)|*.txt"
CommonDialog1.FilterIndex = 2
CommonDialog1.ShowOpen
If CommonDialog1.FileName <> "" Then
Set f = fs.opentextfile(CommonDialog1.FileName, forreading)
Text1.Text = f.readall
f.Close :confused: 
End If
End Sub

The above code is not working.Please correct errors if any

P.S It should prompt a dialog box and open a text file .