if ((screen.width == 1024) && (screen.height ==768))
{
 document.write('<link href=css/medium.css rel=stylesheet type=text/css>'); 
}
else if ((screen.width <1024) && (screen.height <768))
{
 document.write('<link href=css/small.css rel=stylesheet type=text/css>'); 
}
else if ((screen.width == 1152) && (screen.height == 864))
{
 document.write('<link href=css/x-medium.css rel=stylesheet type=text/css>'); 
}
else
{
 document.write('<link href=css/large.css rel=stylesheet type=text/css>'); 
}