CRM 4.0 - Relacionar dos lookups

On Change event (lookup padre)

// Making the skill id lookup null whenver a new values is selected for reesource
crmForm.all.new_numerolookupid.DataValue=null;
crmForm.all.new_numerolookupid.disabled = false;
// getting the value of selected resource
var ar=new Array();
ar=crmForm.all.new_letralookupid.DataValue;
var rID = ar[0].id;
// Changing the display of skillid lookup so that only skill belonging to particular rID should appear
crmForm.all.new_numerolookupid.lookupbrowse=1;
// in the additionalparams for the skill id attribute we will specify the fetch xml query 
// e.g. select * from new_categoryskill (name of our custom skill entity) where
//new_categoryofskillid = rid  

crmForm.all.new_numerolookupid.additionalparams = "fetchXml=";

On Load Form event

// Making the skill id lookup null whenver a new values is selected for reesource
//crmForm.all.new_numerolookupid.DataValue=null;
//crmForm.all.new_numerolookupid.disabled = false;
// getting the value of selected resource
var ar=new Array();
ar=crmForm.all.new_letralookupid.DataValue;
var rID = ar[0].id;
// Changing the display of skillid lookup so that only skill belonging to particular rID should appear
crmForm.all.new_numerolookupid.lookupbrowse=1;
// in the additionalparams for the skill id attribute we will specify the fetch xml query 
// e.g. select * from new_categoryskill (name of our custom skill entity) where
//new_categoryofskillid = rid  

crmForm.all.new_numerolookupid.additionalparams = "fetchXml=";