text: frappe.ui.form.on('Request for Quotation', {
      refresh: function(frm) {
          setTimeout(function(){ 
          cur_frm.fields_dict.items.grid.get_field('item_code').get_query =   
              function() {                                                                      
              return {
                      query: "energielenker.energielenker.item.item.item_query",
                      filters: {'is_purchase_item': 1}
                  }
              }
          }, 1000);
      }
  })
  