Can someone help with this code..PLEASE!

I am basically calling a function when the user selects a row in the grid. What happens is the event appears to be getting triggered TWICE! So I get the alert message show up twice.


//here is how the event handler is set for when the user clicks on a row
obj.setAction("selectionChanged",enableButton);

function enableButton()
{
var rc;
rc = obj.getSelectionProperty("values");
var rowCount = 0;
var printCount = 0;
var data = "";
for (var i=0; i<rowCount; i++)
{
data = obj.getDataProperty("text", rc[i], 0);
if (data.toUpperCase() == "PRINTED")
{
printCount = printCount + 1;
}
} //end of for loop
if (printCount > 1 && rowCount > 1)
{
alert("Unable to Authorize multiple printable items");
printCount = 0;
}
}