<style>a.uw {
  display: inline-block;
  color: white;
  text-decoration: none;
  padding: .5em 2em;
  outline: none;
  border-width: 3px 0;
  border-style: solid none;
  border-color: rgb(51, 175, 253) rgba(0, 0, 0, 0.99) rgba(6, 127, 215, 0.97);
  border-radius: 5px;
  background: linear-gradient(rgba(74, 172, 212, 0.99), rgba(22, 126, 227, 0.98)) rgba(22, 113, 227, 0.97);
  transition: 0.2s;
}  
a.zornet:hover {background: linear-gradient(rgba(58, 151, 187, 0.96), rgba(87, 153, 212, 0.96)) rgba(60, 142, 208, 0.97);}
    a.zornet:active { background: linear-gradient(rgba(0, 150, 245, 0.97), rgba(0, 134, 245, 0.96)) rgba(0, 130, 245, 0.98); }</style>
<script type="text/javascript">  
  function openchat(){new _uWnd('chat','Diskusijas',445,341,{align:0,shadow:0,close:1,autosize:1,maxh:445,minh:341,resize:0}, $("#chat").html() )}  
  </script>  
  <div style="display:none;" id="chat">$CHAT_BOX$</div>

<BR>
<a href="#" class="uw" onclick="openchat();">Diskusijas</a>

maxh:445,minh:341