Something like oEvent.cancelPostBack for DropDownList in asp.net

Hi,


I am having the code for selectedIndexChanged event of a DropDownList in Asp.Net that looks somewhat like this
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
    //Get the value of Base category on the basis of the new index selected.
    
    if(BaseCategory belongs to (SomeValues))
    {
        //do some actions based on the new selected index.
        //Load appropriate UI.
    }
    else
    {
        //Something like
         oEvent.cancelPostBack = true;
         return;

    }

}

I know that I can acheive the same objective by tweaking the code a bit, Bu ...