<html> <body> <script language="JavaScript"> function function1(){ var m = document.getElementById("myDiv").removeAttribute("id"); document.all.myB.innerText = "Click again"; if (m == true) { alert("Attribute removed"); } } </script> <div id="myDiv">This is a div element</div> <div id="myDiv">This is another div element</div> <input id="myB" type="button" value="Remove id attribute" onclick="function1();"> </body> </html>