nctday=new Date();
day=nctday.getDay();

var numberofimages = 7;
images = new Array(numberofimages+1);
images[0] = "<img src='/images/header1.gif'>";
images[1] = "<img src='/images/header2.gif'>";
images[2] = "<img src='/images/header3.gif'>";
images[3] = "<img src='/images/header4.gif'>";
images[4] = "<img src='/images/header5.gif'>";
images[5] = "<img src='/images/header6.gif'>";
images[6] = "<img src='/images/header7.gif'>";

document.write(images[day]);