if (screen.width <= 800) 
{
document.write("<style type='text/css'>body {font-size: 70%;}</style>");
}
else if (screen.width <= 1024) 
{
document.write("<style type='text/css'>body {font-size: 90%;}</style>");
}
else 
{
document.write("<style type='text/css'>body {font-size: 100.01%;}</style>");
}