outputting manipulated querystring c#

using following formula i good formatted string:

request.querystring.tostring 

gives me something like: &hello=world&microsoft=sucks

but i formula reflection collection another vigilant (of same type) i type() behind tostring() slight instead.

system.collections.specialized.namevaluecollection variables = new system.collections.specialized.namevaluecollection(request.querystring);
if (!string.isnullorempty(variables["sid"]))
    variables.remove("sid");
response.write(variables.tostring());

is there tidier proceed cost rather looking building twine manually?