How to add a value to a lookup field in sharepoint 2013?

using (SPSite site = SPContext.Current.Site)
{
    SPFieldLookupValue value = new SPFieldLookupValue();
    site.AllowUnsafeUpdates = true;
    using (SPWeb web = site.OpenWeb())
   {
       web.AllowUnsafeUpdates = true;
       SPList list = web.Lists["ListName"];
       item = list.Items.Add();
       string fieldValue = "Enter the ID" + ";#" + "Enter the Name";
       value = new SPFieldLookupValue(fieldValue);
       item["Column Name"] = value;
       item.Update();
  }
}