custom Picker Callback not working

Hi All,

I tried creating a custom picker using data utility. It is coming on UI but custom picker callback is not working.

I am getting following error:

"It seems that you have not defined the callback function or the there is some error in it: testCallBack exception: ReferenceError: testCallBack is not defined"

Picker Callback:

function testCallBack(objects, pickerID ) {
 alert("in testCallBack");
 	 
var updateHiddenField = document.getElementById(pickerID);
var updateDisplayField = document.getElementById(pickerID +
"$label$");
var myJSONObjects = objects.pickedObject;
for(var i=0; i< myJSONObjects.length;i++) {
var oid = myJSONObjects[i].oid;
//Here “name” is the displayAttribute requested
var displayAttr = eval("myJSONObjects[i].name");
updateHiddenField.value=oid;
updateDisplayField.value=displayAttr;
}

}