Alert Message on Paging in Gridview

Add script to
<script type = "text/javascript">   function Confirm() {
  var confirm_value = document.createElement("INPUT");
  confirm_value.type = "hidden";
  confirm_value.name = "confirm_value";
  if (confirm("Make sure you updated the page before you move?")) {
  confirm_value.value = "Yes";
  } else {
  confirm_value.value = "No";
  }
  document.forms[0].appendChild(confirm_value);
  }
  script>




protected void grid_pageindexchanging(object sender, GridViewPageEventArgs e)
 {
string confirmValue = Request.Form["confirm_value"];
  if (confirmValue == "Yes")
  { 
fncBindGrid();
  }
else
{
 grid.PageIndex = e.NewPageIndex;
  fncBindGrid();
}


}

protected void grid_pageindexchanging(object sender, GridViewPageEventArgs e)
 {
if(e.NewPageIndex<1)
{string script = "";
ClientScript.RegisterClientScriptBlock(this.GetType(), "Alert", script);
}
 }

what you think about this code.

protected void grid_pageindexchanging(object sender, GridViewPageEventArgs e)
 {
string script = "";
ClientScript.RegisterClientScriptBlock(this.GetType(), "Alert", script);

if(script(
{
// do stuff here.....
}
 }