$.ajax({
  url:"<%= eval("new_portlet_"+params[:content_type].tableize.singularize+"_path(:format => 'js')") %>", 
  type: "GET",
  data: { 
    block_id : "<%= params[:block_id] %>",
    position : "<%= params[:position] %>"
    } ,
  success : function (){
    
  }
});