get the control on view in Dynamics

Hello ,

I want to execute to the guid of selected rows from a view .

My probleme is to have the control in the view because the view dosen't exist in the form and to get it I must click in the button that you can visualise it into the first image of picture and the hole view is in second image in the picture  that I want to control it.

I test with the id of subgrid into the html element and I put it into the line :

var selectedRows=Xrm.Page.getControl("crmGrid_listcontact_association_span").getGrid().getSelectedRows();

 but I didn't get any results.

Thank's