Code:
 StrNormalMessage = InputBox(StrInputMessage & IntNumberOFentries, StrInputHeading, "")

        Do Until IntNumberOFentries > intMaxNumberOfEntries
            If IsNumeric(StrGrades) Then
                decGrades = Convert.ToDecimal(StrGrades)
                lstGrades.Items.Add(decGrades)
                If decGrades < 0 Then
                    MsgBox("Please enter a positive number", MsgBoxStyle.Critical, "Grade Book")
                    If decGrades >= 100 Then
                        MsgBox("Please enter a correct value", MsgBoxStyle.Exclamation, "Grade Book")
                    End If
                End If

            End If


            If IntNumberOFentries <= intMaxNumberOfEntries Then
                lblScore.Visible = True
                decFinalGrades = decGrades / IntNumberOFentries
                lblScore.Text = decFinalGrades.ToString

            End If
        Loop
i have NO idea why this isn't working it's worked like this before. I did use just if and end if instead of else and else in my validation of entered data