<html>
<body>
<style>
#myP1 { color:red; font-family:verdana; font-size:16 }
#myP2 { color:green; font-family:times new roman; font-size:18 }
</style>
<p id="myP1">This is a sample text.</p>
<p id="myP2">This is a second sample text.</p>
<input type="button" value="style sheet source" onclick="function1();">
<script language="JavaScript">
function function1() {
var m = document.styleSheets[0].readOnly;
if (m == true) {
alert("The style sheet is defined on the page");
} else {
alert("The style sheet is imported");
}
}
</script>
</body></html>