Need Help making a Auto Refresher

If anyone can help, I need help making a Auto refresher. I need it to be able to go to different URL's everytime it refreshs. The base URL will be the same just the after part will be different. Can anyone help if you have already made one or know where i can get one will be better i am only in my Second Semester of Programming

http://www.whitehouse.net/
Have a look above. hit refresh a few times first. Then have a look at the source.

PHP Code:

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<script language="Javascript">
<!--
// please keep these lines on when you copy the source
// made by: Nicolas - [url]http://www.javascript-page.com[/url]

var currentdate = 0
var core = 0

function StringArray (n) {
  this.length = n;
  for (var i =1; i <= n; i++) {
    this[i] = ' '

  }
}

image = new StringArray(10)
image[0] = '0.gif'
image[1] = '1.gif'
image[2] = '2.gif'
image[3] = '3.gif'
image[4] = '4.gif'
image[5] = '5.gif'
image[6] = '6.gif'
image[7] = '7.gif'
image[8] = '8.gif'
image[9] = '9.gif'

var ran = 60/image.length

function ranimage() {
  currentdate = new Date()
  core = currentdate.getSeconds()
  core = Math.floor(core/ran)
    return(image[core])
}

document.write("<img src='" +ranimage()+ "'>")

//-->
</script> 


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This script will random image on your website... You have to change a few code to random website...

Hint : 1.gif, 2.gif should be change for hyerpink and <img src= for <meta refresh