Collapsible Panels Not working after firing an onload javascript event

Hello All,

I had a webform, wherein I loaded an Update Panel for the whole webform. Inside the Content Template of the Update Panel, I have 5 Panels with Collapsible Panel extenders. Initially the whole webform functioned very well, all the panels were in hidden, and collapsed after hitting the button.

But, later on, I also included a "initialize" javascript in Page Load Event to load a google map, where in I am showing some information on google map in the same webform inside a <div>. Here is the javascript function :- 

if (!ClientScript.IsStartupScriptRegistered("initialize"))
{
Page.ClientScript.RegisterStartupScript(this.GetType(),
"onload", "initialize", true);
}

After inclusion of this thing in page load, All the panels with collapsible extenders were shown in collapsed form, all the panels were collapsed...and even I cant see my button which fires to collapse or hide the panel .

So, can you guys help me out in this regard.

Regards,

Sunny