Position:absolute and centering Options

[GunsNRachel]

I know when you have position: absolute and you put left: 50% it's supposed to center what you want to center.. but mine isn't? I'm confused. It puts it to the right instead of center.

Here's the code:

CODE

.heading{
width:700;
height:300;
background-color:ffffff;
border:0px;
border-color:000000;
border-style:solid;
position:absolute;
left:50%;
font-family:;
color:;
font-weight:normal;
font-size:;
letter-spacing:;}

[schizo]

You have to add margin-left:#px in there. Since the width is 700px, set the number to about -350.