I want to show an loading image with text underneath in a jquery thick box

I am opening an开发者_如何学JAVA iframe in a jquery thickbox . I want to show an loading image with some some text underneath when the iframe gets loaded. I did every login but my problem is how i can create my css in such a way that the loading image and underneath text is at the center of the jquery thickbox in every browser.

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try this--

<div  id="submitPage">
  <img src="loading.gif" alt="">
  Your text...
</div>

#submitPage {
  border: 1px solid black;
  width: 746px;
  height: 201px;
  background: #0ff; 
  z-index: 99;
  position: fixed;
  left: 50%;
  top: 90px;
  margin-left: -373px;
  line-height: 201px;
  text-align: center;
  color: #f00;
}
#submitPage img{
  margin-right: 10px;
  border: none;
}