how to pass parameters in url in httpwebrequest

[kailashprajapat]

how to pass parameters in url in httpwebrequest.
i am developing a site of online mobile recharge in which i hav to use api by calling http://domain_name/api/recharge/uid=_uid&pwd=_p wd.
domain_name,_ui d,_pwd has to passed.
so should it be converted to utf8 format?