.button_gray {margin: 0px 10px;}  
  .button_gray {text-align: center;-webkit-border-radius: 2px;-khtml-border-radius: 2px;-moz-border-radius: 2px;border-radius: 2px;display: inline-block;*display: inline;position: relative;line-height: normal;zoom: 1;}  
  .button_gray {margin: 2px 5px;}  
  .button_gray button {border: 1px solid;background: none;font-size: 11px;margin: 0px;cursor: pointer;white-space: nowrap;outline: none;padding: 4px 14px;*padding: 5px 15px 3px;font-family: tahoma, arial, verdana, sans-serif, Lucida Sans;overflow: visible;}  
  .font_medium .button_gray button {font-size: 12px;}  
  .button_gray button::-moz-focus-inner {border: 0;}  
  .button_gray {border: 1px solid #b3b3b3;background: #e0e0e0;}  
  .button_gray button {border-top-color: #ffffff;border-bottom-color: #e5e5e5;border-left-color: #e7e7e7;border-right-color: #e7e7e7;color: #444;text-shadow:0 1px 0 #ffffff;*border: 0;background: url(http://st0.userapi.com/images/button_vk.png) #dddddd repeat-x top;background-position: 0px -54px;}  
  .button_gray button:hover {background-position: 0px -46px;}  
  .button_gray button:active {background: #dcdcdc;border: 1px solid #dcdcdc;position:relative;}  
  .button_gray {background: url('http://st0.userapi.com/images/upload.gif') center no-repeat;}  
  a.button_gray:hover {text-decoration: none;}  
  /* Серый вид кнопки как в "В контакте" для uCoz от stock-exchange.ucoz.com */  

 

<div class="button_gray"><button>Кнопка</button></div>