asp.net button.Attributes.Add (script not working)...why?

[KathyB]

Hi, I have an asp:button id="btnList" in an asp.net page. In the page
load event (If NOT Postback), I have the following:

btnList.Attributes.Add("onclick", "<script
language='javascript'>window.open('Scanned.aspx', 'Serial Numbers',
'width=200 , height=300, toolbar=no');</script>")

I get no syntax errors, but when I run the page and click the button,
it simply posts back to itself. I made validate false, but don't see
any other

I know this is simple, but PLEASE tell me why???

Thanks, Kathy :-)