// Type the number of images you are rotating.

NumberOfImagesToRotate = 7;

// Specify the first and last part of the image tag.

FirstPart = '<a href="http://www.bostoncorporateportraits.com/"><img src="http://www.bostoncorporateportraits.com/images/headerbw-';
LastPart = '.jpg" alt="Boston Corporate Portraits" border="0"></a>';

function printImage() {
var r = Math.ceil(Math.random() * NumberOfImagesToRotate);
document.write(FirstPart + r + LastPart);
}