Question

Whats wrong with my vba?

Option Explicit
Sub problem2()
Sheet("Sheet2").Select
Dim p As Double, V As Double, d As Double, u As Double
Dim rey As Double
Range(“B1”).Select
p = ActiveCell.Value
Range(“B2”).Select
V = ActiveCell.Value
Range(“B3”).Select
d = ActiveCell.Value
Range(“B4”).Select
u = ActiveCell.Value
Function rey(p, V, d, u)
Range(“B6”).Value
If rey >= 0 And rey <= 2100 Then
MsgBox“Laminar Flow”
ElseIf rey > 2100 And rey < 4000 Then
MsgBox“Transitional Flow”
ElseIf rey >= 4000 Then
MsgBox“Turbulent Flow”
ElseIf rey < 0 Then
MsgBox“Error:Reynolds number must be positive”
End If
End Sub
Function rey(p, V, d, u)
rey = (p * V * d) / u
End Function

Answer 1

Following is the modified code. the code thar I made change is underlined

Option Explicit
Private Sub problem2()
Rem Sheet1("Sheet1").Select
Sheet1.Select
Dim p As Double, V As Double, d As Double, u As Double
Dim r As Double rem rey is a function . so instead or rey , I declare r
Range("B1").Select rem double quotes corrected. delete double quotes and again type from keyboard.
p = ActiveCell.Value   
Range("B2").Select
V = ActiveCell.Value
Range("B3").Select
d = ActiveCell.Value
Range("B4").Select
u = ActiveCell.Value
r = rey(p, V, d, u)    rem to call a function dont write kewword function,and as a function return a rem value store in a variable . r
Range("B6").Value = r
If r >= 0 And r <= 2100 Then
MsgBox "Laminar Flow" rem same double quote problem here. delete and re write double quotes.
ElseIf r > 2100 And r < 4000 Then
MsgBox "Transitional Flow"
ElseIf r >= 4000 Then
MsgBox "Turbulent Flow"
ElseIf r < 0 Then
MsgBox "Error:Reynolds number must be positive"
End If
End Sub

Public Function rey(ByVal p As Double, ByVal V As Double, ByVal d As Double, ByVal u As Double)

rem a function parameter sould be written like above byval/byref parameter as datatype
rey = (p * V * d) / u
End Function

rem call to sub problem2()

Private Sub CommandButton1_Click()
Call problem2
End Sub

rem ---------------------------------------------------------------------

rem output screen