// This is the current document.
// If you are at http://www.foo.com/bar.html?drink=screwdriver, document.location.pathname is "/bar.html"
var currentPage = newPath
 
// This is the list of parameters used to get here
// If you are at http://www.foo.com/bar.html?drink=screwdriver, document.location.search is "?drink=screwdriver"
var currentParameters = document.location.search;
 
// put it all together
var newLocation = "http://www.tdameritrade.com" + currentPage + currentParameters;
 
// to redirect immediately uncomment this
document.location.href = newLocation;