var show = false;

function showtime() {
	var curdate = new Date();
	var min = curdate.getMinutes();
	if(min < 10) min = '0'+min;
	if(show){
		document.getElementById('clock').innerHTML = curdate.getHours()+'<span style="display: inline-block; width: 5px;" id="timer"></span>'+min;
		show = false;
	}else{ 
		document.getElementById('clock').innerHTML = curdate.getHours()+'<span style="display: inline-block; width: 5px;" id="timer">:</span>'+min;
		show = true;
		}
	setTimeout("showtime()",1000);
	}