VBA If else statement

I not sure that I understand what you're doing, but I'll try

Dim Msg1 As String
Dim D As Integer
Dim L As Integer
Dim Ts As Integer
Dim S As Integer
Dim Ci As Integer
Dim Cy As Integer

Msg1 = ComboBox1.Value
D = TextBox1.Value
L = TextBox2.Value

If Msg1 = "Size" Then
    Select Case D
        Case Is >= 0.25
            Ts = 0.001 + (0.006 + 0.005 * D)
        Case Is < 0.25
            Ts = 0.001 + (0.003 + 0.016 * D)
    End Select
    MsgBox Ts

EsleIf Msg1 = "Straightness" Then
    S = L * 0.0087
    MsgBox S


EsleIf Msg1 = "Circularity" Then
    'Can't tell what Size is, so can't correct
    Ci = 0.25 * Size
    MsgBox Ci

ElseIf Msg1 = "Cylindricity" Then
    'S is ALWAYS 0  and Ci is ALWAYS 0 for this test
    '    if S is supposed to be L * 0.0087 then don't put it in the ElseIf above.

    Cy = S + Ci
    MsgBox Cy

End If

End Sub

Thnak's for helping me out with this. Well I am trying to build a user form where it takes value from text box for size D and one for length L and I choose a process in a combobox like size, straightness, circularity and cylyindricity which have different formulas and are associated with each other. So when I enter a size and length and choose a process and hit the command button I want it to calculate the value. So D is a constant and ts, ci, cy are all results which I want to be able to calculate . I am not sure if you understand what i am trying to do? But i could use some assistance on this.