Make a onClick event

How to click on column 1, and alert the value of column 2

I try this, at least try to get the index of the row, but the alert always show the index of the row clicked before ( the one selected) is there a way to alert the one a click on it????????

var btn = new Active.HTML.IMG;
btn.setAttribute("src", "./images/btnDel.jpg");
btn.setEvent("onClick", " alert(row.getItemProperty('index')); ");
obj.setColumnTemplate(bill, 0);

And it there a better way to display a image btn??
Thanks for your help