Public Class Form1

    Sub SetText(ByVal str As String)
        If (str.Chars(0) = "a") Or (str.Chars(0) = "e") Or (str.Chars(0) = "i") Or (str.Chars(0) = "o") Or (str.Chars(0) = "u") Then
            Label1.Text = "You are an " & str
        Else
            Label1.Text = "You are a " & str
        End If
    End Sub
    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        Dim age As Integer
        '
        If Not Integer.TryParse(TextBox1.Text, age) Then
            Label1.Text = "Please enter your age"
        ElseIf (age < 0) Then
            Label1.Text = "Please enter your age"
        ElseIf (age < 1) Then
            SetText("baby")
        ElseIf (age < 13) Then
            SetText("child")
        ElseIf (age < 18) Then
            SetText("teenager")
        ElseIf (age < 65) Then
            SetText("adult")
        ElseIf (age < 120) Then
            SetText("senior")
        Else
            Label1.Text = "Please enter your age"
        End If

    End Sub
End Class