Handheld stylesheet not used on my HTC

I'm using

<link href="stylesheets/mobile.css" rel="stylesheet" type="text/css" media="handheld" />

To include an alternate stylesheet for mobile devices. But it seems that the stylesheet is not being loaded at all on my HTC. Why is this? And more importantly, how do I ma开发者_JS百科ke sure my mobile stylesheet is loaded on all handhelds?

You can view the live website here: www.webvalid.nl/thomas

Thanks in advance!

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I'd recommend using the CSS3 @media screen and (max-width: ###px) media queries as documented nicely at http://webdesignerwall.com/tutorials/css3-media-queries

All HTC (Android ones, anyway) and iPhone browsers support this, as far as I know, due to their good CSS3 support.