function getcss(cssfile){

loadcss = document.createElement('link')
loadcss.setAttribute("rel", "stylesheet")
loadcss.setAttribute("type", "text/css")
loadcss.setAttribute("href", cssfile)
document.getElementsByTagName("head")[0].appendChild(loadcss)

}

if(screen.width <= '800') 
{
getcss('flash/flash800.css') 
}
else if(screen.width > '800' && screen.width <= '1024') 
{
getcss('flash/flash1024.css') 
}
else if(screen.width > '1024' && screen.width <= '1280')
{
getcss('flash/flash1280.css') 
}
else if(screen.width > '1280' && screen.width <= '1440')
{
getcss('flash/flash1600.css') 
}
else 
{
getcss('flash/flash1600.css') 
}