​x
 
<html>
<head>
<script type="text/javascript" src="/jquery/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
  $(".btn1").click(function(){
  $("p").animate({lineHeight:"3em"});
  });
  $(".btn2").click(function(){
  $("p").animate({lineHeight:"1em"});
  });
});
</script>
</head>
<body>
<p>This is a paragraph. This is some more text. This is some more text. This is some more text. This is some more text. This is some more text. This is some more text. This is some more text. This is some more text. This is some more text. This is some more text. This is some more text. This is some more text. This is some more text.</p>
<button class="btn1">Animate</button>
<button class="btn2">Reset</button>
</body>
</html>
​