how can i write onchange event in the drop down box

I am placed the dropdown box in my grid but on change of this dropdown box, I have to do some thing for this I have used the fallowing code but unfortunately this function is not being called. Can any one help me please....

dupSelect.setOptionsProperty("texts", ["Yes","No"]);
dupSelect.setOptionsProperty("values", ["Yes", "No"]);
dupSelect.setOptionsProperty("count", 2);
dupSelect.setAction("selectionChanged", function(src) {
// some code
}
acGrid.setColumnTemplate(dupSelect, 0);

Thanks in advance
Srinath

dupSelect.setAction("onchange", function(src) {
// some code
}

??

on onchange event of the select box (drop down box) i wanted call one javascript function so i tried this , you can ignore it, please do let me know how to call a function ON onchange event

Srinath