function start_timer(){
	setTimeout("showPopup()", 5000);
}

function showPopup() {
	if(document.getElementById('my_div_op')){
	a=document.getElementById('my_div_op');
	a.style.display="block";
	setTimeout("hidePopup()", 20000);
	}
}

function hidePopup() {
	if(document.getElementById('my_div_op')){
	a=document.getElementById('my_div_op');
	a.style.display="none";
	}
}

function hide_close_but() {
  document.getElementById("my_div_op").style.display="none";
}