Filter Subgrid with Javascript - MS CRM 2013

Hi,

I want to filter a subgrid.

My code :

function FilterCasesSubgrid() {
   var CasesSubgrid =Xrm.Page.getControl("lots_associes");
   if(CasesSubgrid==null){ 
        setTimeout(function () { FilterCasesSubgrid(); }, 2000); //if the grid hasn’t loaded run this again when it has 
        return;
    }
    var fetchXml ="<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false'>"+"<entity name='new_lot'>"+"<attribute name='new_name' />"+"<attribute name='new_nomduprogramme' />"+"<attribute name='new_villelookup' />"+"<attribute name='new_loyertotal' />"+"<order attribute='title' descending='false' />"+"<filter type='and'>"+"<condition attribute='new_name' operator='eq' value='004' />"+"</filter>"+"</entity>"+"</fetch>";

//Here i set the fetchxml directly to subgrid
alert("1");
    CasesSubgrid .control.SetParameter("fetchXml", fetchXml); //set the fetch xml to the sub grid  
alert("2");
    CasesSubgrid .control.Refresh(); //refresh the sub grid using the new fetch xml 
}

with that I only have the first alert who says '1'. The last alert isn't displayed and the subgrid isn't modified.

Do you have any idea?