Accessing Reportviewer From Web

Hi,
apologies for what I know is a very basic question. We have a very simple ASP.NET page that includes a report viewer object. The site containing the page is on a public server, and the report server is on an internal server (actually the same physical machine, but running on a different IP) - we are referencing the report server via a 10.x.x.x address and it's not connecting from outside. The report server is not accessible from the public address, and I don't believe there's firewall issues - can someone please point me in the right direction?

thanks,
Steve.

<snip>
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Web.Security;

namespace WebReportTest2
{
/// <summary>
/// Summary description for WebForm2.
/// </summary>
public class WebForm2 : System.Web.UI.Page
{
protected System.Web.UI.HtmlControls.HtmlForm Form1;
protected System.Web.UI.WebControls.DropDownList DropDownList1;
protected System.Web.UI.WebControls.Label Label3;
protected System.Web.UI.WebControls.Label Label4;
protected System.Web.UI.WebControls.DropDownList Dropdownlist2;
protected System.Web.UI.HtmlControls.HtmlForm Form2;
protected System.Web.UI.WebControls.DropDownList Dropdownlist3;
protected System.Web.UI.WebControls.Button btnLogOut;
protected Microsoft.Samples.ReportingServices.ReportViewer ReportViewer1;

private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
//this.DropDownList1.Items.Add(new ListItem("report1,"report1"));

string param = DropDownList1.SelectedValue;
ReportViewer1.ReportPath = "/Development/report1" + param ;
ReportViewer1.ServerUrl = "http://10.72.x.x/reportserver";


}