Gridview自帶分頁問題,謝謝,该怎么解决

Gridview自帶分頁問題,謝謝
有兩頁面A,B,
A向B頁面傳一參數flag,
B頁面判斷flag為1時bind1(),為2時bind2(),頁面高了   AllowPaging= "True "   OnPageIndexChanging= "GridView1_PageIndexChanging "   PageSize= "15 "
PageIndexChanging事件我這樣寫,好像不對

protected   void   GridView1_PageIndexChanging(object   sender,   GridViewPageEventArgs   e)
        {
                GridView1.PageIndex   =   e.NewPageIndex;
                if   (flag   ==   "1 ")
                {
                        bind();
                }
                if   (flag   ==   "2 ")
                {
                        bind1();
                }                
        }

------解决方案--------------------------------------------------------
可能發生碰撞
------解决方案--------------------------------------------------------
if (!IsPostBack)
{
ViewState[flag2] = Request.QueryString[ "flag2 "];

if(ViewState[flag2].Tostring()== "1 ")
{
bind();
}
if(ViewState[flag2].Tostring()== "2 ")
{
bind1();
}
}

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
if (ViewState[flag2].Tostring() == "1 ")
{

bind();
}
if (ViewState[flag2].Tostring()== "2 ")
{
bind1();
}

}