How To remove asp.net registered array in ajax

Dear Friends,
I have a aspx page , which i have some  controls on it.
In my Update panel , I want to refresh array values in my updatepanel's postback.

So each time , in my onpreRender Method , I have registered array values:
scriptmanager.registerArrayDeclaration(value);

but when I look at page source, there is only first values in my array...
AnyBody know what to do?