Centre an Image - php

Question

I'm trying to horizontally center an image. However it does not move from the left side of the page. This answer does not work in my case. What am I doing wrong?
#container {
width: 100%;
border: 2px yellow dashed;
height: 100px;
}
#profile-image img{
margin-left: auto;
margin-right: auto;
border: 2px orange solid;
}
mypage:
<div id="container">
<div id="profile-image">
<p><img src="<?php echo $data['profile_image_url'];?>" alt="me"></p>
</div>

Answer 1

to make any div or anything horizontally at center , common css approach will be,lets have a width and declare margin:0 auto;
#profile-image{
width:400px;
margin:0 auto;
}

Answer 2

Try this: http://jsfiddle.net/rua4d/2/
#container {
width: 300px;
border: 2px yellow dashed;
height: 100px;
display:table-cell;
position:relative;
vertical-align:middle;
}
#profile-image img{
margin-left: auto;
margin-right: auto;
border: 2px orange solid;
display:block;
position:relative;
vertical-align:middle;
text-align:center;
width:50px;
}

Answer 3

You just need to add display:block to your image's style. Images are inline elements, and inline elements ignore margins.

Answer 4

why cant this work?
#profile-image p { text-align: center; }
#profile-image img { display: inline; }
that way you won't need to specify the width.. if you want margins to work together with the text-align: center you would need inline-block instead:
#profile-image p { text-align: center; }
#profile-image img { display: inline-block; }