jquery simple issue
<p>am a newbie with jquery .. i have this html code</p>

<pre><code>&lt;div id='input'&gt;
&lt;table&gt;
    &lt;tr&gt;
    &lt;td class="number"&gt;
    &lt;input&gt;&lt;input&gt;&lt;input&gt;&lt;input&gt;&lt;br&gt;
    &lt;/td&gt;
    &lt;td style="vertical-align:bottom"&gt;&lt;button&gt;+&lt;/button&gt;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
    &lt;td class="number"&gt;
    &lt;input&gt;&lt;input&gt;&lt;input&gt;&lt;input&gt;&lt;br&gt;
    &lt;/td&gt;
    &lt;td style="vertical-align:bottom"&gt;&lt;button&gt;+&lt;/button&gt;&lt;/td&gt;
    &lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
</code></pre>

<p>and for my script part</p>

<pre><code>jQuery.fn.vcenter = function(parent) {
    if (parent) {
        parent = this.parent();
    } else {
        parent = window;
    }
    this.css({
        "position": "absolute",
        "left": ((($(parent).width() - this.outerWidth()) / 2) + $(parent).scrollLeft() + "px"),
    });
return this;
}
jQuery.fn.hcenter = function(parent) {
    if (parent) {
        parent = this.parent();
    } else {
        parent = window;
    }
    this.css({
        "position": "absolute",
        "top": ((($(parent).height() - this.outerHeight()) / 2) + $(parent).scrollTop() + "px"),
    });
return this;
}
jQuery.fn.center = function(parent) {
    if (parent) {
        parent = this.parent();
    } else {
        parent = window;
    }
    this.css({
        "position": "absolute",
        "top": ((($(parent).height() - this.outerHeight()) / 2) + $(parent).scrollTop() + "px"),
        "left": ((($(parent).width() - this.outerWidth()) / 2) + $(parent).scrollLeft() + "px"),
    });
return this;
}
$(document).ready(function(){
$("#input").vcenter(true);
});
$("#input:button").click(this.parent().prev().html()+="&lt;input&gt;&lt;input&gt;&lt;input&gt;&lt;input&gt;&lt;br&gt;");
</code></pre>

<p>what am trying to do basically is each time i click on a button inside the  element that has the id "input"<br>
the script executes the following : the script goes to the parent element (the ) then the previous sibling ! then add to its html inner the following : <code>"&lt;input&gt;&lt;input&gt;&lt;input&gt;&lt;input&gt;&lt;br&gt;"</code><br>
i have done my homework ! and i need help ! what's wrong here ?</p>
