How can i see if a textfield is on the stage?

[geestring]

I have an addChild(tip);

but i want something like
if(tip == true){

removeChild(tip);
}

before the addChild(tip), in order to see if there is a tip, if there is i want to delete it and have the new tip added.

my above code doesnt work

[Scott64]

if(contains(tip)){
removeChild(tip);
}