How do I define two tasks within an "if"-formula using VBA?

I am currently creating an order form for users to fill out.

For that I have created several form fields in a Word document.

For me to make sure that users will fill the appropriate fields, I have created a macro. I succeeded in making a macro that will force the user to enter something in a pop-up box (this is the first "do"-string.

However I want the view to jump to the given field, which is what I am trying to do in the second "do"-string.

This is the code:

Sub mustFill()

    Dim fieldvars(1 To 12) As String
    Dim labels(1 To 12) As String

    fieldvars(1) = "siteName"
    fieldvars(2) = "currentDate"
    fieldvars(3) = "deliveryDate"
    fieldvars(4) = "pcpName"
    fieldvars(5) = "pcpMail"
    fieldvars(6) = "pcpPhone"
    fieldvars(7) = "numberOfTurbines"
    fieldvars(8) = "siteAddress"
    fieldvars(9) = "emergencyPhone"
    fieldvars(10) = "hubHeight"
    fieldvars(11) = "towerSections"
    fieldvars(12) = "coordinateSystem"

    labels(1) = "Site name"
    labels(2) = "Current date"
    labels(3) = "Requested delivery date"
    labels(4) = "Project contact person, Name"
    labels(5) = "Project contact person, E-mail"
    labels(6) = "Project contact person, Phone no."
    labels(7) = "Number of turbines"
    labels(8) = "Site address"
    labels(9) = "Emergency phone no."
    labels(10) = "Hub height"
    labels(11) = "Number of tower sections"
    labels(12) = "Turbine coordinate system, datum and zone"

    For i = 1 To 12
    If ActiveDocument.FormFields(fieldvars(i)).Result = "" Then
    Do
            sInFld = InputBox("This field: " & labels(i) & " is mandatory. Please fill in below.")
    Do
            ActiveDocument.FormFields(fieldvars(i)).SetFocus
        Loop While sInFld = ""
        Loop While sInFld = ""
        ActiveDocument.FormFields(fieldvars(i)).Result = sInFld
    End If
    Next i
End Sub

Is it the string that I have done wrong or is it a problem with multiple "Do"-strings inside the "If"-formula.

Thank you a lot in advance!

/thormann