window.onload=dropdown_onclick;

function dropdown_onclick() {
  if (!document.getElementById("dropline")) {
    return;
  }
  var lis = 
    document.getElementById("dropline").getElementsByTagName("li");
  for (var i=0; i<lis.length; i++) {
    var currentLi = lis[i];
    currentLi.onclick = function(){
		document.getElementById("dropline").getElementsByTagName("li");
				  for (var i=0; i<lis.length; i++) {
					var currentLi = lis[i];
					currentLi.className=currentLi.className.replace(new RegExp(" selected\\b"), "");
				  }
				this.className+=" selected";
				
	};
  }

}