Det här kanske?
<script language="JavaScript">
var outmess= " Välkommen "
var mess1= ""
day = new Date( )
hr = day.getHours( )
if (( hr >= 0 ) && (hr <= 4 ))
mess1= "God natt "
if (( hr >= 4 ) && (hr < 12))
mess1=" God morgon "
if (( hr >= 12) && (hr <= 17))
mess1= "God eftermiddag "
if ((hr >= 17) && (hr <= 23))
mess1= "God kväll "
document.write(mess1)
document.write(outmess)
// --></script>
/Pele