clearTimeout if exists
<p><code>timer_gear</code> exist only in case if I press some button (until 5 sec). But there is another function it can be called any time. In this function I clear the timer and restart it. But first I have to check if the object exists otherwise I get this error:
Uncaught ReferenceError: timer_gear is not defined</p>

<p>Could you help me to solve this? These does not work.</p>

<pre><code>if(timer_gear!="undefined")clearTimeout(timer_gear);

if(timer_gear)clearTimeout(timer_gear);
</code></pre>

<p>EDIT1:
first I misspelled my question: if(!timer => if(timer
EDIT2:</p>

<p>the full code is:</p>

<pre><code>function hide_gear(){
    $('#gear_div').animate({opacity: 0}, 1000);
    delete timer_gear; //EDIT3: destroy object
}
</code></pre>

<p>...</p>

<pre><code>/*gear*/
$('#gear').click(function(){
    $('#gear_div').animate({
        opacity: 1,
      }, 1000, function() {
        timer_gear = setTimeout("hide_gear();",5000);
      });
});
$('#gear').mousemove(function(){
    if( ? ? ? )
    {
        clearTimeout(timer_gear);
        timer_gear = setTimeout("hide_gear();",5000);
    }

});
</code></pre>

<h2>Results:</h2>

<pre><code>timer_gear// Uncaught ReferenceError timer_gear is not defined
timer_gear != undefined // Uncaught ReferenceError: timer_gear is not defined
typeof timer_gear !== "undefined" // WORKS
typeof timer_gear != "undefined" // WORKS, just tired it
var timer_gear; //at the begining - WORKS, but I did not wanted a new variable if its not necessary
</code></pre>

<p>thank you for answers!</p>
