<div class="radius"></div>
.radius{
  width:50px;
  height:50px;
  background:#333;
  border-top-left-radius: 10px; 
  border-bottom-right-radius: 10px;
  -webkit-border-top-left-radius: 10px;
  -webkit-border-bottom-right-radius: 10px;
  -moz-border-radius-topleft: 10px;
  -moz-border-radius-bottomright: 10px;
}

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External JavaScript

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