gridview dropdownlist event

I am trying to add a dropdownlist to pager of gridview. The dropdownlist is added successfully and is populated with the correct values. However when i change the selection the ddlPages_SelectedIndexChanged method is not triggered. the autopostback property is set to true.

any suggesstion please.

protected void GridView1_DataBound(object sender, EventArgs e)
{
GridViewRow gvrPager = GridView1.BottomPagerRow;

if (gvrPager == null) return;

DropDownList ddlPages = (DropDownList)gvrPager.Cells[0].FindControl("ddlPages");
ddlPages.SelectedIndexChanged += new EventHandler(this.ddlPages_SelectedIndexChanged);

if (ddlPages != null)
{
// populate pager
for (int i = 0; i < GridView1.PageCount; i++)
{

int intPageNumber = i + 1;
ListItem lstItem = new ListItem(intPageNumber.ToString());

if (i == GridView1.PageIndex)
lstItem.Selected = true;

ddlPages.Items.Add(lstItem);
}
}
}

protected void Paginate(object sender, CommandEventArgs e)
{
//ss
}

public void ddlPages_SelectedIndexChanged(Object sender, System.EventArgs e)
{
GridViewRow gvrPager = GridView1.BottomPagerRow;
DropDownList ddlPages = (DropDownList)gvrPager.Cells[0].FindControl("ddlPages");

GridView1.PageIndex = ddlPages.SelectedIndex;

// a method to populate your grid
MyDataBind();
}