Anyone with visual basic experience

"Build a form where the user enters a number from 1 to 2500 in a textbox and the program converts it into Roman Numerals output into a label with a prompt."

Need some help on this one, I'm confused on how to do this code but this is what I have so far.

Public Class Form1
'Enter 1 to 2500 converts to Roman Numerials
Dim M As Integer = 1000
Dim CM As Integer = 900
Dim D As Integer = 500
Private Sub btnCalculate_Click(sender As Object, e As EventArgs) Handles btnCalculate.Click
Try
Select Case True
Case (CDbl(txtYear.Text) = 1)
lblAnswer.Text = "I"
Case (CDbl(txtYear.Text) = 2)
lblAnswer.Text = "II"
Case (CDbl(txtYear.Text) = 3)
lblAnswer.Text = "III"
Case (CDbl(txtYear.Text) = 4)
lblAnswer.Text = "IV"
Case (CDbl(txtYear.Text) = 5)
lblAnswer.Text = "V"
Case (CDbl(txtYear.Text) = 6)
lblAnswer.Text = "VI"
Case (CDbl(txtYear.Text) = 7)
lblAnswer.Text = "VII"
Case (CDbl(txtYear.Text) = 8)
lblAnswer.Text = "VIII"
Case (CDbl(txtYear.Text) = 9)
lblAnswer.Text = "IX"
Case (CDbl(txtYear.Text) = 10)
lblAnswer.Text = "X"
Case (CDbl(txtYear.Text) = 50)
lblAnswer.Text = "L"
Case (CDbl(txtYear.Text) = 100)
lblAnswer.Text = "C"
Case (CDbl(txtYear.Text) = 500)
lblAnswer.Text = "D"
Case (CDbl(txtYear.Text) = 1000)
lblAnswer.Text = "M"
End Select
Catch
'Display an error message
MessageBox.Show("Please enter a number 1-2500.")

End Try
End Sub

Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click
txtYear.Clear()
lblAnswer.Text = ""
End Sub

Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
Me.Close()
End Sub
End Class