css - Centralizing a floating element -

My "div" element has a relative width, it is not complete so I do not use specific numbers to centralize can do. A good solution is to use "display: inline-block":

  body {text-align: center; } #myDiv {border: 1px solid black; Display: Inline-block; Padding: 50px; }  

But this element needs to float, I tried to do this:

  #myDiv {border: 1px solid black; Display: Inline-block; Swim left; Padding: 50px; }  

And this:

  #myDiv {boundary: 1px solid black; Display: Inline-block; Padding: 50px; Status: Completed; }  

Without any success, can someone help me?

Thanks

  #myDiv {margin: 0 auto; }