Javacript image banner random rotator

Phew..enough conditions there ?

So, I needed this javascript image rotator which would pick files from a folder and show them randomely rotating through the images ...

Meh.. here is what I googled and searched and figured out 

First put a placeholder on the page...

 <div id="imageDiv">

                        <script language="javascript" type="text/javascript">

                            document.write('<center><img src="' + adBanner1 + '" id="adBanner5" width="620" height="250" border="0" alt="Some Alt Text">');

                            document.write('</center>');

                        </script>

                        <noscript>

                            <img src="/Images/rotate/1.jpg" id="adBanner5" border="0" width="620" height="250"

                                alt="Some ALt Text" /></noscript>

                        </div>

Now, getting a random number ...after all the first image should be random no ??

    <script language="JavaScript" type="text/javascript">

<!--

        rnd.today = new Date();

        rnd.seed = rnd.today.getTime();

        function rnd() {

            rnd.seed = (rnd.seed * 9301 + 49297) % 233280;

            return rnd.seed / (233280.0);

        };




        function rand(number) {

            var result = Math.ceil(rnd() * number);

            if (!result) result++;

            return result

        };

</script>

Now that we have a random number, lets populate the image 

<script language="javascript" type="text/javascript">
//the total number of images to rotate

                  var ad_cnt1 = 20;

        var ad1 = rand(ad_cnt1);

        var link1;

        var adBanner1;

        var width1

        var height1

        var i = 0;

        for (i = 0; i <= ad_cnt1; i++) {

            if (ad1 == i) {

                adBanner1 = "/images/rotate/" + i + ".jpg";

            }

        }                                   </script>




Now... using the rotator to rotate through the images

var currentAd5 = 1;

        function cycle5() {

            if (currentAd5 == ad_cnt1) {

                currentAd5 = 1;

            }

            var banner5 = document.getElementById('adBanner5');

            banner5.src = "/images/rotate/" + currentAd5 + ".jpg";

            currentAd5++;

        }

        window.setInterval("cycle5()", 5000);

Hmm so my final code would look like such:

In the head of the page I put this Javascript :

  <script language="JavaScript" type="text/javascript">

<!--

        function clearText(field) {




            if (field.defaultValue == field.value) field.value = '';




        }




        function restoreText(field) {




            if (field.value == '') field.value = field.defaultValue;




        }




        rnd.today = new Date();

        rnd.seed = rnd.today.getTime();

        function rnd() {

            rnd.seed = (rnd.seed * 9301 + 49297) % 233280;

            return rnd.seed / (233280.0);

        };




        function rand(number) {

            var result = Math.ceil(rnd() * number);

            if (!result) result++;

            return result

        };

        var ad_cnt1 = 20;

        var ad1 = rand(ad_cnt1);

        var link1;

        var adBanner1;

        var width1

        var height1

        var i = 0;

        for (i = 0; i <= ad_cnt1; i++) {

            if (ad1 == i) {

                adBanner1 = "/images/rotate/" + i + ".jpg";

            }

        }

        var currentAd5 = 1;

        function cycle5() {

            if (currentAd5 == ad_cnt1) {

                currentAd5 = 1;

            }

            var banner5 = document.getElementById('adBanner5');

            banner5.src = "/images/rotate/" + currentAd5 + ".jpg";

            currentAd5++;

        }

        window.setInterval("cycle5()", 5000);

-->

    </script>

And where I need to rotate the images I put this div 

  <div id="imageDiv">

                        <script language="javascript" type="text/javascript">

                            document.write('<center><img src="' + adBanner1 + '" id="adBanner5" width="620" height="250" border="0" alt="Some Alt Text">');

                            document.write('</center>');

                        </script>

                        <noscript>

                            <img src="/Images/rotate/1.jpg" id="adBanner5" border="0" width="620" height="250"

                                alt="Some Alt Text" /></noscript>

                        </div>

By the way "window.setInterval("cycle5()", 5000);" does the rotation at 5 sec interval... you can change it to suit your needs

And you are welcome