I would like to run a js function on pressing Enter button.
Everything works great in IE, Chrome and Opera, but I get an error (explained below) in Safari.

I need a pure Javascript solution, not jQuery.

This is the function:

function pressSearch(e) {

    if (typeof e == 'undefined' && window.event) {

        e = window.event;

    }

    var charCode = (e.which) ? e.which : 

                   ((e.charCode) ? e.charCode : 

                   ((e.keyCode) ? e.keyCode : 0));

    if (charCode == 13) {

        document.getElementById('enterSearch').click();

    }

}

This is the HTML:

<input type=text id=searchKey onkeypress=pressSearch(event)>

<div id=enterSearch>Search</div> // This is the button

I get this error:

// Safari

TypeError: 'undefined' is not a function 

    (evaluating 'getElementById('enterSearch').click()')

What am I doing wrong?

EDIT: I've fixed the Mozilla Firefox error.