how to check is this is a asp or asp.net

hello, i am a php coder... but now i am working in asp website.. just easy task.. adding a captcha on there.. but i am confuse...
how to do that.. and i get some information that asp & asp.net is differently
how to check what the code on the site that i am working on (asp or asp.net) ?

** sorry if my english not good
thanks

 

i feel, i have got this answer
asp using file extension = .asp
asp.net using file extension = .aspx

thanks

 

view source code and if u can see viewstate thng ther it's usually asp.net else it's classic asp, asp and asp.net are different u can google about 'em to get gud answer

 

There is many differences. The filename is a good start, also if the code contains a datatype for variable declarations then it is asp.net. for example:
asp:
Dim myStr

asp.net:
Dim myStr As String

Also asp.net code will most likely have controls within the html, like:
<asp:Button ID="mybutton"></asp:Button>

Another giveaway is event handlers within the code:
Private Sub Page_Load(ByVal sender As Object ... ... etc.