how to use ASP.NET api in android

Question

I m using android to call asp.net api, but i dont know how to do this. required Request and Response is attached below:

api link is like :

http://gateway.xxx.xxx.com.np/websrv/Service.asmx

Request is like:

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:xsd="http://www.w3.org/2001/XMLSchema"xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
    <UserLists xmlns="xxx">
        <Id>string</Id>    
        <UserName>string</UserName>
        <Password>string</Password>
        <Datetime>string</Datetime>
        <Signature>string</Signature>
    </UserLists>
</soap:Body>
</soap:Envelope>

Response is like:

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:xsd="http://www.w3.org/2001/XMLSchema"xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
    <UserListsResponse xmlns="xxx">
        <UserListsResult>
            <UserLists>
                <Name>string</Name>
                <Code1>string</Code1>
                <CODE2>string</CODE2>
                <MESSAGE>string</MESSAGE>
            </UserLists>
            <UserLists>
                <Name>string</Name>  
                <Code1>string</Code1>
                <CODE2>string</CODE2>
                <MESSAGE>string</MESSAGE>
             </UserLists>
         </UserListsResult>
    </UserListsResponse>
</soap:Body>

I've spend too much time to study other online tutorials but did not get any clear understanding and useful solution. Please help me. Thanks in advance.