Vb6 source code is not compiling.

I am trying to compile a source code of vb6 name building the time tracking system. The problem is somewhere in procedure. Kindly let me know the solution. The code is
Private Sub cmdOK_Click()
Dim sngBilledTime As Single, iMinutes As Integer, iHours As Integer
Dim iResponse As Integer
If txtAmountOfTime.Text = "0.00" Then
Msgbox "Your must enter the time spent."
txtAmountOfTime.SetFocus
Exit Sub
ElseIf txtBillingRate.Text <= 0 Then
Msgbox " You must enter the Billing Rate."
txtBillingRate.SetFocus
Exit Sub
ElseIf lblBillingName.Caption = " " Then
lblBillingName.Caption = InputBox("Please enter your name:")
End If
iResponse = Msgbox("Do you want to perview the invoice?", vbYesNo, "Invoice")
If iResponse = vbNo Then
End
Else
Load frmInvoice
With frmInvoice
.lblBilledBy .Caption = frmBillingInfor.lblBillingName
.lblClient .Caption = frmBillingInfo.lstClient.Text
.lblDate .Caption = frmBillingInfo.mskDate.Text
.lblRate.Caption = Format(frmBillingInfo.txtBillingRate.Text, "Rs ####.00")
.lblWorkCategory .Caption = frmBillingInfo.cboCategory.Text
If frmBillingInfo.optByHour.Value = True Then
.lblHourOrJob.Caption = "an Hour"
iMinutes = Val(Right(Me.textAmountOfTime.Text, 2))
iHours = Left(Me.txtAmountOfTime.Text, (InStr(1, Me.txtAmountOfTime.Text, ":") - 1))
Select Case iMinutes
Case Is < 15
If iHours > 0 Then
sngBilledTime = iHours
Else
sngBilledTime = 0.5
End If
Case Is >= 15 And iMinutes <= 30
sngBilledTime = iHours + 0.5
Case Is > 15 And iMinutes <= 30
sngBilledTime = iHours + 1
End Select
.lblTotalAmount.Caption = Format(frmBillingInfo.txtBillingRate.Text * sngBilledTime, "Rs####.00")
.lblTotalTime.Caption = sngBilledTime
Else
.lblHourOrJob = "form item"
.lblTotalTime = "N/A"
.lblTotalAmount = Format(.lblRate.Caption, "Rs####/00")
End If
End With
Unload Me
frmInvoice.Show
End Sub
On compilation the message "invalid use of property" is coming and invoice window is not displayed.