Check if element appended already w/ jQuery -

i need modify function. when condition met element appended. need add check see if element has been added, because can added once.

function checkbox() {  if ($("#mybox").find('.myclass').length == 0)  {    $("#mybox").append(         $('<a href="" id="newbox">click</a>')    );     }  } 

function checkbox() {     if (!$("#mybox").find('.myclass').length) {         $("#mybox").append('<a href="" id="newbox">click</a>');     } } 

check working example http://jsfiddle.net/nybtv/