NumberOfImagesToRotate = 12;

FirstPart = '<img src="fotky/';
LastPart = '.jpg" id="RotatingImage1" alt="" name="RotatingImage1" width="280" height="210" align="top" border="0" >';

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