getElementsByName() property access all elements which we will specify in it.
<html>
<head>
<script type="text/javascript">
function getNumberOfElements()
{
var x=document.getElementsByName("btn");
alert(x.length);
}
</script>
</head>
<body>
<input name="btn" type="button" value="First" />
<input name="btn" type="button" value="Second" />
<input name="btn1" type="button" value="Third" />
<input name="btn" type="button" value="Forth" />
<input name="btn" type="button" value="Fifth" />
<input name="btn" type="button" value="Sixth" /><br /><br />
<input type="button" onclick="getNumberOfElements()" value="Click here to find the number of elements that have the same name" />
</body>
</html>
In this example the alert box shows the number of button element (btn).