actionscript onClipEvent argument flash MX

[cathiec]

i have a piece of action script that takes a string in one text box and searches through text in another to find that string. if the string is found then it is highlighted.
i set the error:

Scene=Scene 1, Layer=Slides, Frame=3: Line 6: Invalid movie clip event specified.
onClipEvent(search_btn){

here is the actionscript:

// place code like this in the frame containing the searchable text, search string and search button
onClipEvent(search_btn){
stop();
/* d - is the instance id of the text field to be searched
s - is the instance id of the text (input) field to be searched for
search_btn - is the instance id of the search button placed in the frame with
the text fields
*/

var begin:Number; // beginning index of search string
var len:Number; // length of search string

TF = new TextFormat(); // text format for italic
TF.italic = true;

btnListener = new Object();
btnListener.click = function () {
begin = _root.d.text.indexOf(_root.s.text); // find the beginning of the string
len = _root.s.text.length; // find the length of the search string
d.setTextFormat(begin, begin + len, TF); // change the format of the located text
}

search_btn.addEventListener ("click", btnListener); // listener for search button

}


do i have the wrong argument in the onClipEvent?