Login page not working in vb asp.net - asp.net

Question

I am having an issue with my login page. I am not getting any errors so am not able to know where the problem is?
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Login.Click
'connection string
Dim mysqlconn As MySqlConnection = New MySqlConnection("server=localhost;user id=root;Password=123;database=users;persist security info=False")
Dim cmd As New MySqlCommand
Dim da As New MySqlDataAdapter
Dim mydata As New DataTable
Dim reader As MySqlDataReader
Try
mysqlconn.Open()
Dim query As String
query = "SELECT * FROM login_form where Username = '" & rfvUser.Text & "' and Password='" & rfvPWD.Text & "'"
cmd = New MySqlCommand(query, mysqlconn)
reader = cmd.ExecuteReader
While reader.Read()
If rfvUser.Text = "admin" And rfvPWD.Text = "admin" Then
Me.Session("User") = Me.rfvUser.Text
Server.Transfer("Admin.aspx")
ElseIf (rfvUser.Text = reader("UserName").ToString()) And (rfvPWD.Text = reader("Password").ToString()) Then
Me.Session("User") = Me.rfvUser.Text
Server.Transfer("Ersal_send.aspx")
Else
ClientScript.RegisterStartupScript(Page.[GetType](), "validation", "<script language='javascript'>alert('Invalid Username or Password')</script>")
reader.Close()
End If
End While
Catch ex As Exception
MsgBox(ex.Message)
Finally
mysqlconn.Dispose()
End Try
End Sub
End Class

Answer 1

Have you tried running the query directly via a SQL client? If your query is not returning any rows, then your procedure will simply exit without any errors as it will never enter the While loop.
Another advice: It is never a good idea to pass user input directly into a query. This leads to SQL injection. Use parameterised queries. Google for it.