Retreive XML element/node name of grid column

I load XML data with a random number of columns in a grid. How can I retreive the element/node name of a specific column in the onCellValidated event?

You can use getCellModel() method to get access to the XML datasource and then getNode() method -

grid.onCellValidated = function(text, col, row){
    var table = this.getCellModel();
    var node = table.getNode(col, row);
    alert(node.nodeName);
}