<span <% if level < max_level && r != ''%>
onmouseover="$('<%=row_id%>_plusminus').show();"
onmouseout="$('<%=row_id%>_plusminus').hide();"
...
<span <% if level < max_level && r != ''%>
onmouseover="$('<%=row_id%>_plusminus').show();"
onmouseout="$('<%=row_id%>_plusminus').hide();"
...
Definitely new to Ruby and ...