var date=new Date(); // Gets the full date!
var day=date.getHours(); // Gets the hours!

if(day<=11) {
document.write('<img src="../images/good-morning-madame.jpg" alt="Good Morning" />'); // If it's before 12 PM then display this!
} else if(day<18){
document.write('<img src="../images/good-afternoon-madame.gif" alt="Good Afternoon" />'); // After 12 PM display this!
} else {
document.write('<img src="../images/good-evening-madame.jpg" alt="Good Evening" />'); // After 6 PM display this!
}