How to call non-static method from static web method

 [System.Web.Services.WebMethod]
public static DataSet GetContactName()
{ DataSet ds = new DataSet();
XmlDocument doc = new XmlDocument();
ds.ReadXml(System.Web.HttpContext.Current.Server.MapPath("App_Data/Group.xml"));
LoadData(ds); ?????
}

I need to bind this ds to a repeater control.

public void LoadData(DataSet ds)
{
DataSet ds = GetContactName();
repeaterGroup.DataSource = ds;
repeaterGroup.DataBind();
}

My question is, how to call LoadData from above webmethod. LoadData() method is not recognized from the webmethod.
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