Dim length, iwidth, a, b, totallength, totalrolls, remainder As Integer

Private Sub cmdCalculate_Click()
'resets length and width variables
length = 0
iwidth = 0
'retrieves length and width from the textboxes
length = Val(txtlength.Text)
iwidth = Val(txtwidth.Text)
'tests that length and width are numbers
If Not IsNumeric(txtlength.Text) Then
    MsgBox ("You must enter a number for the length.")
    txtlength.Text = ""
    txtlength.SetFocus
End If
If Not IsNumeric(txtwidth.Text) Then
    MsgBox ("You must enter a number for the width.")
    txtwidth.Text = ""
    txtwidth.SetFocus
End If
'tests that length and width are within 1 and 20 metres
If IsNumeric(txtlength.Text) Then
If length < 1 Or length > 20 Then
    MsgBox ("You must enter a length between 1 and 20")
    txtlength.Text = ""
    length = 0
    iwidth = 0
    txtlength.SetFocus
End If
End If
If IsNumeric(txtwidth.Text) Then
If iwidth < 1 Or iwidth > 20 Then
    MsgBox ("You must enter a width between 1 and 20")
    txtwidth.Text = ""
    txtwidth.SetFocus
    length = 0
    iwidth = 0
End If
End If
'calculates total length of carpet needed
a = iwidth \ 5

If iwidth Mod 5 > 0 Then
 a = a + 1
End If

totallength = a * length
lbltotallength.Caption = Str(totallength) + " metres"
'calculates total rolls needed
b = (a * length)

totalrolls = b \ 30

If b Mod 30 > 0 Then
    totalrolls = totalrolls + 1
End If

lbltotalrolls.Caption = totalrolls
'calculates length of excess carpet roll (with 5m width)
remainder = (totalrolls * 30) - totallength

lblremainder.Caption = Str(remainder) + " metres"

End Sub

Private Sub cmdExit_Click()

End

End Sub

Private Sub cmdReset_Click()

txtlength.Text = ""
txtwidth.Text = ""
lbltotallength.Caption = "0"
lbltotalrolls.Caption = "0"
lblremainder.Caption = "0"

End Sub