How can I select something specific on iWeb?

Hola!

What I mean by this is, every time I try to select: text, picture, menu bar, etc, etc. Something else interferes... I wish could lock some layers, like you can do in Photoshop or Illustrator. When that happens, not only its annoying and a waste of time, but also it changes place from being in the back to the front * covering other things...

Any experience superstar out there? 😉