Probably not the greatest way of doing it but a simple method to get the query string in JavaScript would be to just use something along the lines of:
a = "http://www.domain.com?queryArg1=somequeryargument";
query = a.substring(a.indexOf('?')+1);
You could then split the query up based on the &'s and again on the = to get at whatever param you need.
Sorry if this ain't very helpful as its a bit of a low tech method :P
EDIT:
Just wrote a quick little JavaScript object to get URL Query parameters for you (sort of like) in your example. Only tested it in chrome but in theory it should work :)
//Quick and dirty query Getter object.
function urlQueryGetter(url){
//array to store params
var qParam = new Array();
//function to get param
this.getParam = function(x){
return qParam[x];
}
//parse url
query = url.substring(url.indexOf('?')+1);
query_items = query.split('&');
for(i=0; i<query_items.length;i++){
s = query_items[i].split('=');
qParam[s[0]] = s[1];
}
}
//Useage
var bla = new urlQueryGetter("http://www.domain.com?queryArg1=somequeryargument&test=cheese");
alert(bla.getParam('test'));