SMART datagrid v.1 > Classes > GridBase
If Cell Style specified by styleid has been registered in CellStyleManager, it will return true.
var sm = grid.styleManager();
// If there is the style which has styleid named 'style1', it will be applied to the fourth cell of fifth row.
if (grid.existsCellStyle('style1')) {
sm.setStyleAt(4, 3, 'style1');
};