Calling function to execute javascript code

I would like to place a javascript (adsense) code inside the post (not above or after the post). It will be a HTML page.

Is there any way i can put my adsense code in external Js file and i will use one function to display it. adsense code looks something like

<scrip开发者_StackOverflow中文版t type="text/javascript"><!--
google_ad_client = "pub-xxxxxxxxxxxxxxxx";
google_ad_host = "pub-xxxxxxxxxxxxxxxx";
google_ad_slot = "xxxxxxxxxx";
google_ad_width = 336;
google_ad_height = 280;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>

So if i call a function CallMe() which will start showing ad wherever i have used the function. In future if i would like to replace ad code with another code then i dont want to go to each post and replace it. I will just replace the adcode from js file.

I am a newbie and have just started learning JavaScript so i am really not aware if it can be done or not.

Any suggestion ?

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Create file called AdSense.js with the following code:

google_ad_client = "pub-xxxxxxxxxxxxxxxx";
google_ad_host = "pub-xxxxxxxxxxxxxxxx";
google_ad_slot = "xxxxxxxxxx";
google_ad_width = 336;
google_ad_height = 280;
function ApplyAdSense() {
    var oScript = document.createElement("script");
    oScript.type = "text/javascript";
    oScript.src = "http://pagead2.googlesyndication.com/pagead/show_ads.js";
    document.getElementsByTagName("head")[0].appendChild(oScript);
}

Now whenever you want adsense in your code, first include the file:

<script type="text/javascript" src="AdSense.js"></script>

Then call the function:

<script type="text/javascript">
    ApplyAdSense();
</script>

This way, until you call the function nothing happens.. and you can also comment the code inside the function to disable adsense throughout all your site.

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Wherever you want the ad to show up, place this code (assuming you have a function called CallMe).

    <some html>
        <script type="text/javascript">CallMe();</script>
    </some html>

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If your concern is about the page loading time, Adsense released the asynchronous version of their Adsense code. Please see https://support.google.com/adsense/answer/3221666?hl=en