'contains()' Example
<html> <body> <script language="JavaScript"> function function1() { var flag = document.all.myDiv.contains(myB); if (flag == true){ flag = "YES" } else { flag = "NO" } alert(flag) } </script> <div id="myDiv" style="width:300; height:100; border:solid; 1px blue">div element<br> <input id="myB" type="button" value="Is this button contained within the div element?" onclick="function1();"> </div> </body> </html>