title: UpdatePanel doesn't Refresh
body: <p>I have got a simple page with a HtmlInputHidden field. I use Javascript to update that value and, when posting back the page, I want to read the value of that HtmlInputHidden field. The Value property of that HtmlInputHidden field is on postback the default value (the value it had when the page was created, not the value reflected through the Javascript). I also tried to Register the HtmlInputHidden field with ScriptManager.RegisterHiddenField(Page, "MyHtmlImputHiddenField", "initialvalue") but it still only lets me read the 'initialvalue' even though I (through javascript) can inspect that the value has changed.</p>
  
  <p>I tried to hardcoded the rowid and, to my surprise, after postback gridview was exactly the same before the delete but the record was deleted from the database. (I´ve called the databind method). </p>
  
  <pre><code>  protected void gridViewDelete(object sender, GridViewDeleteEventArgs e)
    {
  
        bool bDelete = false;
        bool bCheck = false;
  
        if (hfControl.Value != "1")
        {
            // check relationship
            bCheck = validation_method(.......);
            if (bCheck)
            {
                bDelete = true;
            }   
        }
        else
        {
            hfControl.Value = "";
            bDelete = true;
        }
  
        if (bDelete)
        {
            //process delete
        }
        else
        {
            string script = string.Empty;
  
            script += " var x; ";
            script += " x = confirm('are u sure?'); ";
            script += " if (x){ " ;
            script += " document.getElementById('hfControl').value  = '1'; ";
            script += " setTimeOut(__doPostBack('gridView','Delete$"
                                        + e.RowIndex + "'),0);";
            script += " } ";
  
            ScriptManager.RegisterClientScriptBlock(this,
                                         Page.GetType()
                                         , "confirm"
                                         , script
                                         ,true);
        }
     } 
  </code></pre>