Send the tablet version instead the regular version

Hi Guys,

I would like know what kind of script I need to make to detect the screen resolution and apply the tablet version of the site, instead of the regular version.

I found this, example, but It requires two html.

<SCRIPT language="JavaScript">

<!--

if ((screen.width>=1024) && (screen.height>=768))

{

window.location="highres.html";

}

else

{

  window.location="lowres.html";

}

//-->

</SCRIPT>