In latest version of HTML (HTML 5.0), CENTER tag is deprecated. So instead of using Tag <center>..</center>, you can use text-align:center. 'text-align' property doesn't actually aligns the division, it aligns the text content within the division.
Inline -
<div style="text-align:center">your content...</div>
Css -
.center {
text-align:center
}
<div class="center">your content...</div>