dhtmlxGrid combobox


I’m having two comboboxes (c1 and c2) inside a dhtmlxGrid. The problem is when i select a value from c1 it gets selected correctly. When i select a value from c2, the value corresponding to the index of c1 is selected (not c2 value). What is the way for differentiating two comboboxes inside grid?.

Please, make sure that each combo column has a unique name.
For example:
combo1 = grid.getCombo(1);
combo2 = grid.getCombo(3);

Thank you