combining loops

any help on how i would combine these two loops into one do while loop?
thanks!

VB Code:

If (num > 1) Then
            Do While (num > 1)
                Do While (num Mod num1) = 0
                    num2 = num \ num1
                    If (num2 > 1) Then
                        txt2 &= num1 & " * "
                        num = num2
                    Else
                        txt2 &= num1
                        num = 0
                        Exit Do
                    End If
                Loop
                If (num = 0) Then Exit Do
                num1 += 1
            Loop
            lblOutput.Text = "Prime factors of " & number & " are: " _
            & txt1 & txt2
        End If
    End Sub

A Do loop just checks a boolean expression. The expression can be as simple as a single Boolean literal or as complex as you like:

VB Code:

Do While num > 0 AndAlso num Mod num1 = 0