jQuery Grid Plugin - jqGrid

I am using a subgrid to represent a master/detail model. All is working perfectly. One little 'Visual' drawback is if a master does not yet have any detail records then we still get the + expand sign and when we expand it we just get the headings, as there is no records. Is it possible to either:

1.Change the + sign to nothing or anoher icon or make it not clickable if no records

But i presume as the click loads the subgridurl to get the data for that id that would be difficult as we need to know ALL the data upfront.

2. When clicking the + if no records do not expand, possible?

To be honest it is only a visual thing, but would be nice.

Regards

Mark C.