var Id;
function setcolour()
{
var r = (Math.random() *256).toString(16);
var g = (Math.random() *256).toString(16);
var b = (Math.random() *256).toString(16);
var colourString = "#" + r + g + b;
document.bgColor = colourString;
 Id=setTimeout('setcolour()',1500);
}