VS 2010 Infinity Error

Could someone please tell me why I am getting an Infinity error when I try to get the average daily cost of gas?
I think this is why my total average is not working out.

Public Class Form1

Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
'Clear all fields
txtKilometres.Text = ""
txtGasMileage.Text = ""
txtPriceLitre.Text = ""
lblTotalGas.Text = ""
txtVacationDays.Text = ""
txtMeals.Text = ""
txtHotel.Text = ""
txtIncidentials.Text = ""
txtEntrance.Text = ""
lblTotal.Text = ""
lblAverage.Text = ""
txtKilometres.Focus()

End Sub
Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click

'Geclare variables
Dim dblKilometres As Double
Dim dblGasMileage As Double
Dim dblPriceLitre As Double
Dim dblTotalGas As Double
Dim dblVacationDays As Single
Dim dblMeals As Double
Dim dblHotel As Double
Dim dblIncidentials As Double
Dim dblEntrance As Double
Dim dblTotal As Double
Dim dblAverage As Double
Dim dblTotalHotel As Double
Dim dblTotalNights As Double
Dim dblTotalMeals As Double
Dim dblTotalIncidentials As Double



'Set variables
dblKilometres = Val(txtKilometres.Text)
dblGasMileage = Val(txtGasMileage.Text)
dblPriceLitre = Val(txtPriceLitre.Text)
dblTotalGas = Val(lblTotalGas.Text)
dblVacationDays = Val(txtVacationDays.Text)
dblMeals = Val(txtMeals.Text)
dblHotel = Val(txtHotel.Text)
dblIncidentials = Val(txtIncidentials.Text)
dblEntrance = Val(txtEntrance.Text)
dblTotal = Val(lblTotal.Text)
dblAverage = Val(lblAverage.Text)


'Calculate total cost of gas
dblTotalGas = ((dblKilometres * dblGasMileage) / 100 * dblPriceLitre)

'Calculate how many night in hotel room
dblTotalNights = dblVacationDays - 1

'Calculate total cost of meals
dblTotalMeals = dblMeals * dblVacationDays

'Calculate total cost of hotel rooms
dblTotalHotel = dblTotalNights * dblHotel

'Calculate total cost of incidentials
dblTotalIncidentials = dblIncidentials * dblVacationDays

'Calculate total cost
dblTotal = dblTotalMeals + dblTotalHotel + dblTotalIncidentials + dblEntrance + dblTotalGas

'Calculate average per day
dblAverage = dblTotal + dblTotalGas / dblVacationDays


lblTotalGas.Text = Format(dblTotalGas, "C")
lblTotal.Text = Format(dblTotal, "C")
lblAverage.Text = Format(dblAverage, "C")
End Sub

'
End Class