hide cancel button in ribbon Sharepoint listItem form

<script type="text/javascript">
var elem = document.getElementById("Ribbon.DocLibListForm.Edit.Commit.Cancel-Large");
elem.style.display = "none";
setInterval(abc,3000);
function abc()
{
var x=document.getElementsByTagName("input");

for (var i=0; i < x.length; i++)
{
if (x.item(i).type=="button" && x.item(i).value=="Cancel")
{

x.item(i).style.display="none";
}
}
}

</script>