试图调整由<？php include（“”）调用的页面的大小; ？>

Question

I've created a fixed, slide down header with jquery. When you click on the buttons, they pop open a div with content inside of it. One of these opens another page inside of the div.. I'm trying to figure out how to resize the page inside of the div. Both the header and footer are fixed (it's the way the client wants it), so there isn't much room.

Here's my base code, just looking for the right direction!

<div class="settingsbtn" style="position: relative; top: 20px; right: 100px;">Close X</div>
            <div class="settingsdiv" style="height: 50%; width: 50%;">
            <?php include("admin/adminheader.php"); ?>
            </div>
</div>

I don't know if you needed the jquery or CSS I'm using for the pop out divs, here's that just incase...

.settingsdiv {
position: absolute;
right: 195px;
top: 60px;
display: none;
height: 500px;
width: 800px;
overflow: hidden;
background: white;

}

.settingsbtn {
cursor: pointer;
}

    $('.settingsbtn').click(function(){
    $('.settingsdiv').toggle(200);
    });

I'm sure I'm just missing something silly. Google just hasn't been much help in the matter.

Thanks in advance!