How To Get Lookup ID,Name and EntityType in CRM 2011

First Write a function to get lookup

    function GetLookup(FieldName) {

    var lookup = Xrm.Page.data.entity.attributes.get(FieldName)

    if (lookup == null) { return null; };

    var lookupObj = lookup.getValue();

    return lookupObj[0];     

 }

1- To Get Lookup Id.

    function GetLookupId(fieldName) {

    var lookup = GetLookup(fieldName);

    if (lookup != null) {

        return lookup.id;

      }

    return null;

  }

2- To Get Lookup Name.

 function GetLookupName(fieldName) {

    var lookup = GetLookup(fieldName);

    if (lookup != null) {

        return lookup.name;

      }

    return null;

  }

3- To Get Lookup Entity Type. 

    function GetLookupEntityType(fieldName) {

    var lookup = GetLookup(fieldName);

    if (lookup != null) {

        return lookup.entityType;

      }

    return null;

  }