Call JavaScript function from an ASP.NET AJAX enabled Content Page

If your content page is wrapped in an ASP.NET AJAX UpdatePanel, then you cannot use the ClientScript.RegisterStartupScript to call a JavaScript function during a partial-page postback. Instead, use the ScriptManager.RegisterStartupScript() method.
protected void Page_Load(object sender, EventArgs e)
System.Text.StringBuilder sb = new System.Text.StringBuilder();

ScriptManager.RegisterStartupScript(this, this.GetType(), “ajax”, sb.ToString(), false);