Getting ASP.NET servers to send some specific HTML for non Microsoft browsers

I suspect I am just missing something simple here, but I have a situation where the html sent to IE via some simple ASP.NET pages that I am futzing about with render fine in IE as expected, Also as expected render like bat guano on non IE browsers like Mozilla, Opera, and Firefox.

Now if I take the actual HTML stream from IE by examining source and compare it to the source sent to say firefox I can see that several of the parameters sent to IE are missing in the html streamed by IIS to the non microsoft browser. Presumabily these browsers don't support these parameters on the controls ( Text boxes are an example ).

But If I save the IE HTML to a file and open that file in the non IE browser I get perfectly rendered output in the non IE browser. So the browser does allow these parameters but IIS is just not sending them.

My question is how do I get IIS to expand its output to include these parameters on more browsers than just IE?.

(I have tried numerous browser ID strings settings with no luck) so my thought is that there is something else the IIS and ASP.NET are doing to detect what broswer I am using. ( Some expanded browser caps settings for example )

I'm sure the flames are coming but I have my fire retardant on so do your worst!