NameValueCollection data = new NameValueCollection();

data.Add("v1", "val1");

data.Add("v2", "val2");

HttpHelper.RedirectAndPOST(this.Page, "http://DestUrl/Default.aspx", data);

/// 

/// POST data and Redirect to the specified url using the specified page.

/// 

/// The page which will be the referrer page.

/// The destination Url to which

/// the post and redirection is occuring.

/// The data should be posted.

/// Samer Abu Rabie

public static void RedirectAndPOST(Page page, string destinationUrl, 

                                   NameValueCollection data)

{

//Prepare the Posting form

string strForm = PreparePOSTForm(destinationUrl, data);

//Add a literal control the specified page holding 

//the Post Form, this is to submit the Posting form with the request.

page.Controls.Add(new LiteralControl(strForm));

}

/// 

/// This method prepares an Html form which holds all data

/// in hidden field in the addetion to form submitting script.

/// 

/// The destination Url to which the post and redirection

/// will occur, the Url can be in the same App or ouside the App.

/// A collection of data that

/// will be posted to the destination Url.

/// Returns a string representation of the Posting form.

/// Samer Abu Rabie

private static String PreparePOSTForm(string url, NameValueCollection data)

{

    //Set a name for the form

    string formID = "PostForm";

    //Build the form using the specified data to be posted.

    StringBuilder strForm = new StringBuilder();

    strForm.Append("
 + formID + "\" name=\"" + 

                   formID + "\" action=\"" + url + 

                   "\" method=\"POST\">");

    foreach (string key in data)

    {

        strForm.Append(" + key + 

                       "\" value=\"" + data[key] + "\">");

    }

    strForm.Append("");

    //Build the JavaScript which will do the Posting operation.

    StringBuilder strScript = new StringBuilder();

    strScript.Append(");

    strScript.Append("var v" + formID + " = document." + 

                     formID + ";");

    strScript.Append("v" + formID + ".submit();");

    strScript.Append("");

    //Return the form and the script concatenated.

    //(The order is important, Form then JavaScript)

    return strForm.ToString() + strScript.ToString();

}