css html programming Quick Tips

Centering an HTML table with CSS

As you may have noticed, the table align=”center” attribute has been deprecated. So how is one supposed to center a table in an HTML page? The answer is with CSS. However, this is not as straight forward as you would think. Basically we now need to inform the browser to put the same amount of empty space on either side of our tables. Here is how to do it:

The inline method

<table style="margin:auto;">

Or if you are using an attached stylesheet you can do it with either classes or the ID method, or by further defining the table tag.

Here are some lines from a CSS stylesheet showing all three methods (you only need to use one of them, so choose what works best for you)

/* this will define the table tag */
table { margin:auto }
/* this will define an ID to assign the style to */
# table_align { margin:auto }
/* and lastly this is a css class that can be used */
.table_align { margin:auto }

Now, here is the html to make use of these three methods

<table class="table_align" id="table_align">

NOTE: Using “margin:auto” is a bit of overkill since it is basically affecting the margin on all 4 sides of the table in some way. You could center the table more precise by using the margin-left:auto and margin-right:auto and setting two properties in CSS. However, I usually find that the regular margin:auto generally does the job when the top and bottom are not a concern.

Unfortunately IE (Internet Explorer) once again is different and chooses not to recognize any of the methods above. So you will be forced to do one of two things.

  1. Add the margin:auto style to your “body” tag OR
  2. Resort to still using the align=”center” attribute for your tables to satisfy IE


<body style="margin:auto">
<table align="center">

I do not like the previous two examples, but sometimes you gotta do what it takes to reach your entire audience.

css html javascript php programming prototype Quick Tips

CSS style sheet switcher using Prototype

A recent project had a requirementfor a style switcher allowing a visitor to control font size on the site as needed. (Many do not know how to change it through a browser, and most sites are not designed to allow for font size changes without completely trashing presentation.)

Because the project in question was a dynamic site I wanted to make a style sheet switcher that didn’t force a page reload and it seemed like most examples on the net required a page to reload with a new stylesheet. (After PHP or some other scripting language decided which css sheet to render the page with.) This meant additional calls to the server to repopulate data grids and other info, after re-running a query and parsing in PHP. To me this was truly unacceptable load on a server to simply change font sizes on a page.