Gridview within an UpdatePanel does not render in the DOM

protected void Page_Load(object sender, EventArgs e)
{
    string js = "$(document).ready(function(){$("#" + this.TextBox1.ClientID + "").text('hello world');});";
    HtmlGenericControl script = new HtmlGenericControl("script");
    script.Attributes.Add("type", "text/javascript");
    script.InnerHtml = js;
    Page.ClientScript.RegisterStartupScript(this.GetType(), "key", js, true);
}