HowTo change the status on IsPostBack

[Margret]

My project:
After login the StartingUserControl opens where DropDownLists fills up and
another UserControl (TableUserControl) loads in aswell with empty TextBoxes.
If I change a value in one DropDownList the TableUserControl won't load.

What I want to do is when I change a value in this first DropDownList,
everything will be like when I first loaded the page except for a one
variable.

Is it possible to change the status of the IsPostBack to false without
initializing every DropDownList and TextBox on the page ?

Any ideas are appreciated Thanx !