Web Forms :: Call A Function During Sql Select To Show Progress Bar

I am trying to call somehting reall simple like Label1.visible = true; while a rather cumbersome sql select is exicuting for a particular page.

I've tried to call it like this:

protected void GridView1_DataBinding(object sender, EventArgs e)
{
Label1.Visible = true;
}
and I tried like this:

protected void SqlDataSource1_Selecting(object sender, SqlDataSourceSelectingEventArgs e)
{
Label1.Visible = true;
}

with no luck

WHERE to call it, and if there is cool progress bar function too, that would be bonul. (But im OK with a generic animated gif or lable)