​x
 
<!DOCTYPE html>
<html>
<head>
<script>
function displayResult()
{
    var x=document.getElementById("fname");
    x.value=x.value.toUpperCase();
}
</script>
</head>
<body>
​
<p>在输入域松开按键时触发函数。该函数将小写字母转为大写字母。</p>
输入你的名字: <input type="text" id="fname" onkeyup="displayResult()">
​
</body>
</html>