banner refresh code

I have banner code, which is not like images and hyperlinks. All I need is the javascript code that will refresh this code every 30 seconds without refreshing the rest of the page.

This banner code will be appear in chatroom. I would really appreciate any help. The banner code:

<script language='JavaScript' 
        type='text/javascript' 
        src='xxxxxx/ban开发者_JAVA技巧ner.php?uname=yyyy&type=2&rows=1' >    
</script>

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First thing you should do is wrap your code in a function. Trying to re-invoke an entire scripting file import is much more difficult than just invoking a function.

Once everything is wrapped in a function, you can use setTimeout to invoke the method. I would do something like this:

function drawBanner() {
    // Do stuff to draw the banner.
    // Make sure you handle the case that the
    // banner is already present in the DOM!
}

function onDrawBannerTimer() {
    // Set this function to fire again after 30 seconds.
    // Note that this will fire it roughly every 30 seconds real-time.
    // You can move this statement to after the drawBanner() call
    // in order to make it 30 seconds between the end of one
    // invocation and the start of the next.
    setTimeout(onDrawBannerTimer, 30 * 1000);
    drawBanner();
}

// Trigger the first invocation when the script is loaded.
onDrawBannerTimer();

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you'll want to give that script tag an ID (such as id='dynScript') and then have another script block that does pretty much the following: [Note: I'm using jQuery]

<script>
  $(document).ready(function(){

    setTimeout ( $('#dynScript').attr('src','xxxxxx/banner.php?uname=yyyy&type=2&rows=1'), 3000);
  }); 
</script>