Random bgcolor change

<script>

// Select fade-effect below:

// Set 1 if the background may fade from dark to medium

// Set 2 if the background may fade from light to medium

// Set 3 if the background may fade from very dark to very light light

// Set 4 if the background may fade from light to very light

// Set 5 if the background may fade from dark to very dark

var fade_effect=3

// What type of gradient should be applied Internet Explorer 5x or higher?

// Set "none" or "horizontal" or "vertical"

var gradient_effect="horizontal"

// Speed higher=slower

var speed=60

///////////////////////////////////////////////////////////////////////////

// CONFIGURATION ENDS HERE

///////////////////////////////////////////////////////////////////////////

var browserinfos=navigator.userAgent

var ie4=document.all&&!document.getElementById

var ie5=document.all&&document.getElementById&&!browserinfos.match(/Opera/)

var ns4=document.layers

var ns6=document.getElementById&&!document.all

var opera=browserinfos.match(/Opera/) 

var browserok=ie4||ie5||ns4||ns6||opera

if (fade_effect==1) {

    var darkmax=1

    var lightmax=127

}

if (fade_effect==2) {

    var darkmax=127

    var lightmax=254

}

if (fade_effect==3) {

    var darkmax=1

    var lightmax=254

}

if (fade_effect==4) {

    var darkmax=190

    var lightmax=254

}

if (fade_effect==5) {

    var darkmax=1

    var lightmax=80

}

var hexc = new Array('0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F')

var newred

var newgreen

var newblue

var oldred

var oldgreen

var oldblue

var redcol_1

var redcol_2

var greencol_1

var greencol_2

var bluecol_1

var bluecol_2

var oldcolor

var newcolor

var firsttime=true

  

var stepred=1

var stepgreen=1

var stepblue=1

function setrandomcolor() {

    var range=(lightmax-darkmax)

    if (firsttime) {

        newred=Math.ceil(range*Math.random())+darkmax

        newgreen=Math.ceil(range*Math.random())+darkmax

        newblue=Math.ceil(range*Math.random())+darkmax

        firsttime=false

    }

     

    oldred=Math.ceil(range*Math.random())+darkmax

    oldgreen=Math.ceil(range*Math.random())+darkmax

    oldblue=Math.ceil(range*Math.random())+darkmax

     

    stepred=newred-oldred

    if (oldred>newred) {stepred=1}

    else if (oldred<newred) {stepred=-1}

    else {stepred=0}

     

    stepgreen=newgreen-oldgreen

    if (oldgreen>newgreen) {stepgreen=1}

    else if (oldgreen<newgreen) {stepgreen=-1}

    else {stepgreen=0}

     

    stepblue=newblue-oldblue

    if (oldblue>newblue) {stepblue=1}

    else if (oldblue<newblue) {stepblue=-1}

    else {stepblue=0}

    fadebg()

}

function fadebg() {

    if (newred==oldred) {stepred=0}

    if (newgreen==oldgreen) {stepgreen=0}

    if (newblue==oldblue) {stepblue=0}

    newred+=stepred

    newgreen+=stepgreen

    newblue+=stepblue

     

    if (stepred!=0 || stepgreen!=0 || stepblue!=0) {

        redcol_1 = hexc[Math.floor(newred/16)];

        redcol_2 = hexc[newred%16];

        greencol_1 = hexc[Math.floor(newgreen/16)];

        greencol_2 = hexc[newgreen%16];

        bluecol_1 = hexc[Math.floor(newblue/16)];

        bluecol_2 = hexc[newblue%16];

        newcolor="#"+redcol_1+redcol_2+greencol_1+greencol_2+bluecol_1+bluecol_2

        if (ie5 && gradient_effect!="none") {

            if (gradient_effect=="horizontal") {gradient_effect=1}

            if (gradient_effect=="vertical") {gradient_effect=0}

            greencol_1 = hexc[Math.floor(newred/16)];

            greencol_2 = hexc[newred%16];

            bluecol_1 = hexc[Math.floor(newgreen/16)];

            bluecol_2 = hexc[newgreen%16];

            redcol_1 = hexc[Math.floor(newblue/16)];

            redcol_2 = hexc[newblue%16];

            var newcolorCompl="#"+redcol_1+redcol_2+greencol_1+greencol_2+bluecol_1+bluecol_2

            document.body.style.filter=

"progid:DXImageTransform.Microsoft.Gradient(startColorstr="+newcolorCompl+", endColorstr="+newcolor+" GradientType="+gradient_effect+")"

        }

        else {

            document.bgColor=newcolor

        }

        var timer=setTimeout("fadebg()",speed);

    }

    else {

        clearTimeout(timer)

        newred=oldred

        newgreen=oldgreen

        newblue=oldblue

        oldcolor=newcolor

        setrandomcolor()

    }

}

if (browserok) {

    window.onload=setrandomcolor

}

</script>

<html>

<head>

<title>background</title>

<script language="javascript">

function add()

{

document.g.r1.value

=parseInt(document.g.n1.value)

+parseInt(document.g.n2.value)

}

function sub()

{

document.g.r1.value

=parseInt(document.g.n1.value)

-parseInt(document.g.n2.value)

}

function div()

{

document.g.r1.value

=parseInt(document.g.n1.value)

/parseInt(document.g.n2.value)

}

function mul()

{

document.g.r1.value

=parseInt(document.g.n1.value)

*parseInt(document.g.n2.value)

}

function mod()

{

document.g.r1.value

=parseInt(document.g.n1.value)

%parseInt(document.g.n2.value)

}