<html>
<body>
<script language="JavaScript">
function function1() {
alert(document.all.tags("p").length);
}
</script>
<p>This is a sample text.</p>
<p>This is another sample text.</p>
<p>This is another sample text.</p>
<p>This is another sample text.</p>
<p>This is another sample text.</p>
<p>This is another sample text.</p>
<p>This is another sample text.</p>
<p>This is another sample text.</p>
<p>This is another sample text.</p>
<p>This is another sample text.</p>
<p>This is another sample text.</p>
<input type="button" value="Number of p elements" onClick="function1();">
</body>
</html>