hi sachin mca2012,
I checked that arif ansari's code is working f9 you can go with following as well,
protected void Button1_Click(object sender, EventArgs e)
{
ScriptManager.RegisterStartupScript(this, this.GetType(), "ShowSuccess", "callit()", true);
}
and put below code in script tag in head tag
<script type="text/javascript">
function callit()
{
alert("call successfull");
}
</script>
in button click event put your all data saving code before this register script if you data insertion will not be success this code execution will not go to this line..