select by id in jquery
<p>as all you know</p>

<pre><code>$("#ID")  
</code></pre>

<p>returns the element having ID.</p>

<p>but this code always return  even there's no element.</p>

<pre><code>alert($("#htrBuyerCouponNotice"));
alert(document.getElementById("htrBuyerConponNotice"));
</code></pre>

<p>in this case.</p>

<p>those two line results are diffrent. </p>

<p>I want to check whether  there is an element  has <code>htrBuyerCouponNotice</code>.</p>

<p><code>document.getElementByID</code>  return null  if there's no element.</p>
