Fileupload cancel's other image

Good day,
I have a fileupload command onto my asp.net site. It runs fine to upload an image but when I go to upload a second image into the textbox it does cancel the first one and just show the string and upload the second image and show it in the texbox.
This is my code behind my vb file.
Protected Sub btnUpload_Click(sender As Object, e As System.EventArgs) Handles btnUpload.Click If FileUpload1.HasFile Then Try lblerror.ForeColor = Drawing.Color.Red FileUpload1.SaveAs(Server.MapPath("~/kb/images/") & FileUpload1.FileName) Dim FileName As String = System.IO.Path.GetFileName(FileUpload1.PostedFile.FileName) Dim strfullpath As String = "http://intradev.gnb.ca/nbisakb/kb/images/" & FileName.ToString tbnotes.Text += ("<img src=" & strfullpath & " >") ...