var today = new Date ()
var hrs = today.getHours();

if (hrs <= 12)
        document.write("<small><font color='red' face='Arial'><b>Good Morning.</b></font></small>");
else if (hrs <= 18)
        document.write("<small><font color='red' face='Arial'><b>Good Afternoon.</b></font></small>");
else
     document.write("<small><font color='red' face='Arial'><b>Good Evening.</b></font></small>");