I'm trying to create a salesforce task in c#. Succeeded in creating a task programatically but couldn't set the Subject, Name and Related To field values.

C# Code for setting field values

sObject newTask = new sObject();

sObject[] tasks = new sObject[1];

System.Xml.XmlElement[] taskElement = new System.Xml.XmlElement[6];

System.Xml.XmlDocument taskDocument = new System.Xml.XmlDocument();

taskElement[0] = taskDocument.CreateElement("Owner");           

taskElement[0].InnerText = info.userFullName;

taskElement[1] = taskDocument.CreateElement("Status");

taskElement[1].InnerText = "Not Started";

taskElement[2] = taskDocument.CreateElement("Subject");

taskElement[2].InnerText = "Call";

taskElement[2].InnerXml = "Call";

taskElement[3] = taskDocument.CreateElement("Priority");

taskElement[3].InnerText = "Normal";

taskElement[4] = taskDocument.CreateElement("WhoId"); 

taskElement[4].InnerText = "003U0000003bY5UIAU"; //id of the Contact that is to be associated

taskElement[4].InnerXml = "003U0000003bY5UIAU";

taskElement[5] = taskDocument.CreateElement("WhatId");

taskElement[5].InnerText = "500U0000000rxp3IAA"; //id of the Case/Opportunity that is to be associated

askElement[5].InnerXml = "500U0000000rxp3IAA";

newTask.type = "Task";

tasks[0] = newTask;

SaveResult[] saveResult = service.create(tasks);

In CreateElement, I tried with "Subject" for subject field and "WhoId" for Contact field and "WhatId" for RelatedTo field but still no value is populated when the task is created. Any suggestion fixing this would be appreciated.

-Kayal