Specify which button to run on event vb.net - vb.net

Question

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim rows, column, j, i
rows = 4
column = 13
For j = 0 To rows - 1
Dim r As New TableRow()
For i = 0 To column - 1
Dim c As New TableCell()
If i = 0 And j = 0 Then
c.Text = "TIME/COURT"
r.Cells.Add(c)
ElseIf i = 0 And j = 1 Then
c.Controls.Add(New LiteralControl("Court A"))
r.Cells.Add(c)
ElseIf i = 0 And j = 2 Then
c.Controls.Add(New LiteralControl("Court B"))
r.Cells.Add(c)
ElseIf i = 0 And j = 3 Then
c.Controls.Add(New LiteralControl("Court C"))
r.Cells.Add(c)
ElseIf i >= 1 And j = 0 Then
c.Controls.Add(New LiteralControl(x & "-" & x + 1))
r.Cells.Add(c)
x += 1
Else
btn = New Button
btn.ID = "btnr" & j & "c" & i
AddHandler btn.Click, AddressOf Change_Colour
c.Controls.Add(btn)
r.Cells.Add(c)
End If
Next
booktable.Rows.Add(r)
Next
End Sub
Protected Sub Change_Colour(sender As Object, e As EventArgs)
btn.BackColor = Drawing.Color.LightGreen
End Sub
When I click on any of the button, only the last button turns light green.
How can I set the button to run the event when I click it?
Can I call the button by button.ID? How?

Answer 1

If multiple buttons can call your Change_Colour routine them you will need to actually determine which one did call it. so you will need something like:
Protected Sub Change_Colour(sender As Object, e As EventArgs)
Dim btn as Button = Ctype(sender, Button)
'here you will need to determine which button is the sender which you could do by checking its name for example
'eg Select case btn.name
'case add stuff here
'end select
btn.BackColor = Drawing.Color.LightGreen
End Sub