jQuery Grid Plugin - jqGrid

Hi all,
in my grid i've a column of action in witch there are buttons for each row to edit/save/restore every row.
When i edit one row, before calling saveRow method, i want to validate input data in 'client mode' using settings specified like:

...
{name:'email', index:'email', width:200, align:'left', sortable:true, editable:true, resizable:false, search:false,
edittype:"text",
editrules:{required:true, email:true}},
...

Can i obtain this ??

And ... if i want to validate same input data in 'server mode' i must use onerrorfunc method specified in saveRow parameter ...
How can i format error response ??

Thanks.