jQuery Grid Plugin - jqGrid

I have 2 fields departDate and arriveDate and in the save of edit/add I need to check the arriveDate is greater then the departDate

I create custom function for the arriveDate field but I didnt know how to get the value of the departDate.

I put the edit button in the gridComplete function:

for(var i=0;i < ids.length;i++){
  var cl = ids[i];
  be = "<input style='height:22px;width:20px;' type='button' value='E' onclick="jQuery('#"+subgrid_table_id+"').jqGrid('editRow',"+cl+",true,pickdates);" />";
  se = "<input style='height:22px;width:20px;' type='button' value='S' onclick="jQuery('#"+subgrid_table_id+"').saveRow('"+cl+"');" />";
  ce = "<input style='height:22px;width:20px;' type='button' value='C' onclick="jQuery('#"+subgrid_table_id+"').restoreRow('"+cl+"');" />";

jQuery("#"+subgrid_table_id).jqGrid('setRowData',ids[i],{act:ce+se+be});

}

so the user doesn't need to select the row before he press on the edit so I cant get the select row id and try to take the value from there.

Any solution?

thanks!