suggest me to display all gridview at a time which is inside accordion panel

I have three accordion panel..A,B,C

Inside Accordion panel A i has gridview1
Inside B.i hasgridview2
Inside C,I has gridview 3.
Outside I has button..
If i click button my 3 gridview should display at a time..
so I used selectedindex..

btn_click(...)
{
/*binded gridview...*/
accordion.selectedindex=0
accordion.selectedindex=1
accordion.selectedindex=2
}


though i called 3 selected index my gridview not displayin..oly one gridview displayin at a time