trouble programmatically adding chart to web form

[User (Legacy)]

i am trying to add a chart to a web form programmatically using c#.  when i

use the following code:

Response.Write(chart1.GetHtmlTag(700,500,"AUTO"));

Everything seems to work fine, specifically the url drill downs.  However,

if i try to add the control using the following code:

this.Contrals.Add( chart1 );

the drill down urls don't seem to work.

Any ideas as to why this is?  Am i adding the chart the right way?

thanks,

--chris