Three buttons and one gridview

use RadioButtonList set autoPostback true and  then  on

OnSelectedIndexChanged event

do following coding

 protected void PupulateGrid(object sender, EventArgs e)    {
        switch (RadioButtonList1.SelectedItem.Value)        {
            case "1":                GridView1.DataSource = "";
                GridView1.DataBind();                break;            case "2":
                GridView1.DataSource = "";                GridView1.DataBind();
                break;            case "3":
                GridView1.DataSource = "";                GridView1.DataBind();
                break;        }        }