How to use SharePoint’s default modal popup from code behind?

A while ago I needed to create a shopping basket. When you click on an item in that basket it would be nice if that item opens in a modal popup. But how can you access the default SharePoint modal popup dialog if it isn’t in your masterpage?

I used following code:

public static class Helper
{
    public static string GetDialogURL(string url, bool refreshOnClose, double width, double height)
    {
        string str = string.Concat(new object[]
		{
            "SP.UI.ModalDialog.showModalDialog({ url:'",
			url,
			"',tite: 'Move Documents',allowMaximize: true ,showClose: true,width:",
			width,
			",height:",
			height
		});
        if (refreshOnClose)
        {
            str += ",dialogReturnValueCallback: function(dialogResult){SP.UI.ModalDialog.RefreshPage(dialogResult)}";
        }
        str += "});";
        return str;
    }
    public static string GetDialogURL(string url)
    {
        return Helper.GetDialogURL(url, true, 700.0, 800.0);
    }
}