Is this true? it is not possible to change the content of the buttons in the dialog displayed by the confirm function

This is my code to display a pop-up the our user to confirm his data:
Code:
            Queue queue = (Queue)(handlerPages[HttpContext.Current.Handler]);
            if ((queue != null))
            {
                StringBuilder builder = new StringBuilder();
                int iMsgCount = queue.Count;
                builder.Append("<script language='javascript'>");
                string sMsg = string.Empty;
                while ((iMsgCount > 0))
                {
                    iMsgCount = iMsgCount - 1;
                    sMsg = System.Convert.ToString(queue.Dequeue());
                    sMsg = sMsg.Replace("\"", "'");

                    string[] QueueArray = sMsg.Split(',');
                    builder.Append("if(confirm( \"" + QueueArray[0] + "\" )) {");
                    builder.Append("location.replace('pageA.aspx?');");
                    builder.Append("} else {");
                    builder.Append("location.replace('pageB.aspx?');");
                    builder.Append("}");
                }
                builder.Append("</script>");
                handlerPages.Remove(HttpContext.Current.Handler);
                HttpContext.Current.Response.Write(builder.ToString());
            }
The user wants to see Yes/No instead of OK/Cancel. It's true I can't use confirm?

I did not write this code and I'll admit I don't understand it, so the first thing I will do is dissect it. But do I also have to rewrite it?

Thanks.