Tracking words in an input txt box

Ok so basically my problem is I have an input box and I want it to track if anywhere in the text box a certain word is typed then something happens. Here is what I got so far.


wordTracker = new Object();
wordTracker = function () {
if(txt_input.split == "word"){
trace("success");
}
}
Key.addListener(wordTracker);

but it doesn’t work. An example of what i want to happen is for instance lets say the user enters this into the txt box
“I like to type a word into documents” because the word “word” was typed in there it would trigger the trace action but it doesn’t how do i get this to work?[SIZE=5][/SIZE]