Poor man's subdomain redirect using JavaScript

gistfile1.js

var hostarray = new Array();

hostarray["subdomain.somewhere.com"] = "subdomain.somewhere.com/application/home.html";

function redirect()
{
    //Obtain the host name in lowercase format
    var lhost = new String(location.host);
    lhost = lhost.toLowerCase();

    //Does a redirect exist for this host?
    if (typeof(hostarray[lhost])!='undefined')
    {
        //Replace the first instance in the location - this retains all extensions/parms
        var newURL = String(location.href);
        var lnewURL = newURL.toLowerCase();

        //Get the exact position of the text to replace
        //(the text should logically be present but we'll confirm it just in case)
        var pos = lnewURL.indexOf(lhost);
        if (pos>=0)
        {
            var hostname = new String(hostarray[lhost]);

            // Strip off leading slashes - this will interfere with parms
            var parms = newURL.substr(pos+lhost.length);
            if ((parms.length > 0) && ((parms.charAt(0) === '\\') || (parms.charAt(0) === '/')))
                parms = parms.substr(1,parms.length-1);

            // Build the new URL with the new replacement for the hostname
            newURL = newURL.substr(0,pos) + hostname + parms;

            //We must be careful NOT to pass any ending slashes because this
            //could interfere with HTM files and parameters in the replacement URL
            //(e.g., http://shortcut.net/  is replaced by  http://replacement.net/home.htm/
            //       we don't want the slash after .htm, now do we?)
            lastchar=newURL.charAt(newURL.length-1);
            if ((lastchar=='\\') || (lastchar=='/'))
                newURL = newURL.substr(0,newURL.length-1);

            // We're ready to load the new URL
            location.replace(newURL);
        }

    }

}