The code below works, insomuch that if I click in an input field, it'll add another row. I'm trying to figure out though, how to do that only if the input field is empty?

$("#tableSearchData > tbody > tr > td > input").bind('focus', function(){
                var row = $(this).closest("tr").get(0);
                if( row.className.indexOf("clicked")==-1 )
                {
                    var rowCopy=$(row).clone(true);
                                $(row).closest("tbody").append(rowCopy);
                                row.className+=" clicked";
                }
});