randomimage = new Array();
randomimage[0] = "1";
randomimage[1] = "2";
randomimage[2] = "3";
randomimage[3] = "4";
randomimage[4] = "5";
randomimage[5] = "housingdevelopment";
randomimage[6] = "industrialcrane";
randomimage[7] = "wetlands";



//calculate a random index
index = Math.floor(Math.random() * randomimage.length);

//display the quotation
document.getElementById('randomheader').innerHTML="<img src=\"/_assets/images/randomheader/" + randomimage[index] + ".jpg\" alt=\"Photograph\" />";