I create a form using excels VB editor. What I have is 5 variable and 5 textboxes for the variables. The program is suppose to allow the user to enter a "TOT POPSIZE" and "ErrorSize", Than once the Calc button is press three results will display in three other textbox which would be a Condidence of 90 answer, Confidence of 95 answer and a Confidence of 99.

Now, my problem is the input textbox should never =0 if they do a MsgBox should appear with a return statement. Can someone help me finish the IF statement. BELOW is my sample code. I know not to sharp that's why I'm here for help!!

Private Sub CommandButton1_Click()

Dim PopSize, ErrSize, ConfUnc90, ConfUnc95, ConfUnc99 As Double

ErrSize = CDbl(txtbox1)

PopSize = CDbl(txtbox2)

If ErrSize = 0 Then

MsgBox ("Population Size should be > 0")

Else

PopSize = 0

MsgBox ("Population Size should be > 0")

Else

ErrSize = eval(form.ErrSize.Value)

form.PopSize.Value = "" + PopSize

form.ErrSize.Value = "" + ErrSize

ConfUnc90 = (0.680625 / ((ErrSize / 100) * (ErrSize / 100)))

ConfUnc95 = (0.9604 / ((ErrSize / 100) * (ErrSize / 100)))

ConfUnc99 = (1.658944 / ((ErrSize / 100) * (ErrSize / 100)))

ConfUnc90.Value = "" + Math.Round(ConfUnc90)

ConfUnc95.Value = "" + Math.Round(ConfUnc95)

ConfUnc99.Value = "" + Math.Round(ConfUnc99)

ConfSamp90.Value = "" + Math.Round((ConfUnc90 * PopSize) / (ConfUnc90 + PopSize))

ConfSamp95.Value = "" + Math.Round((ConfUnc95 * PopSize) / (ConfUnc95 + PopSize))

ConfSamp99.Value = "" + Math.Round((ConfUnc99 * PopSize) / (ConfUnc99 + PopSize))

End If

End Sub