No reason not to nest them:

Code:
 
if ($network == MyNet) {
  echo -a It's MyNet
  if ($chan == #MyChan) {
    echo -a ...and I'm on #MyChan
  }
  elseif ($chan == #YourChan) {
    echo -a ...but I'm on #YourChan
  }
}
else {
  echo -a No idea what Net I'm on
}


Note how much the indenting helps to work out which if/else combinations are associated.