Alighning iframe inside div

1

I need to use iframe in one of the projects and I am having a hard time centering it within div


<div id="iframe">
<iframe id="content" name="content" src="content/index.php" frameborder="0" scrolling="no" align="middle"></iframe>
</div>

but the iframe still stays to the left.

css


#iframe { 
    width: 600px; 
    height: 800px; 
    min-width: 600px;
    max-width: 600px;
    min-height: 800px;
    z-index: auto;
    clear: none;
    padding-left: 10px;
    padding-bottom: 20px;
}