[gears-users] Message if empty resultset

[meerkat]

Hello,

using the Gears api how do you inform the user that there are no
records returned?

while (rs.isValidRow()) {
  console.log(rs.fieldName(0) + " == " + rs.field(0));
  rs.next();
}
rs.close();

I want the opposite of rs.isValidRow() I think but adding !
rs.isValidRow()  crashes the script.

any suggestions? I am sure it must be simple.
meerkat