DIV between two floated images isn't sizing properly - css

Question

I need to create a dialog box using custom images created by a designer. For purposes of this discussion, this the correct answer for my application. The dialog box must be able to withstand changes in width and height. This is easy to do with a table, but I want to maintain a table-less design, so I figured that I could do this using 3 rows of DIV's. For example, float an image to the left, float an image to the right, and put a DIV in between then with the image set to the background so that text can be entered over it.
Here is demo of my failed attempt to do this: (just one row shown)
http://www.seaburydesign.com/rounded/demo.html
As you can see, this almost working. But the DIV in the middle is only the size of the content inside of it, even though I have set the height and width. I need to keep the width flexible.
Any ideas on how to fix this?

Answer 1

Remove the following line:
display:inline;
Besides being useless in this case (the inline behavior is already working because of the floats) "inline" property doesn't allow you to set the element's width or height. For a clearer understanding, read w3c's article.

Answer 2

If you make the rounded corners of your images white instead of transparent, you can apply the background-image to the header-tag instead of the middle div. This will create the impression that the middle div has the same height as both images.
Update
If possible (depending on what browsers you need to support), you could do rounded corners with CSS3's border-radius property, instead of using images. That would be something like:
header {
-webkit-border-top-left-radius: 10px;
-webkit-border-top-right-radius: 10px;
-moz-border-radius-topleft: 10px;
-moz-border-radius-topright: 10px;
border-top-left-radius: 10px;
border-top-right-radius: 10px;
}
You could also try this border-radius CSS-generator to find the properties that suit you best.

Answer 3

The css display: inline in your container div's voids any setting for width. Use display: block; float: left; margin: 0 XXpx; for your div (with XX being the width of the images on the sides).
Edit:
Concretely this would be:
div#yourdiv {
background-image: url("images/module_header_bg.jpg");
color: white;
display: block;
float: left;
font-weight: bold;
height: 42px;
width: auto;
}
and both img tags
img {
float: left;
}
This creates a dynamic sized box for your content, or you set width of the div to a specific value like width: 300px instead of width: auto.