.net - Unable to send required set of tags in response to a web method -

i trying call method service hosted @ client ip , 1 of method need response string . method needs response string following tags :

<a> <user>abc</user> <userdetails>xyz</user details> <userdetails>asd</userdetails> <userdetails>qwe</userdetails> </a>

i have created custom class generate response

class a{ public string user{get;set;} public string [] userdetails {get; set} }

i facing issue while populating user details every time convert object xml object userdetails modified

<userdetails> <string>xyz</string> <string>qwe</string> </userdetails>

kindly suggest solution how can output user details as

<a> <user>abc</user> <userdetails>xyz</userdetails> <userdetails>qwe</userdetails> </a>

Alconcel