The PI property of the Math object is used to get the constant PI.
This is approximately 3.14159.
<html> <body> <script language="JavaScript"> <!-- function doMath(){ var result = Math.PI; document.form1.answer.value = result; } --> </script> <form name=form1> The Approximate value of PI is: <input type="text" name="answer" size=20> <input type="button" value="Calculate" onClick='doMath()'> <br> </form> </body> </html>