var myselect = document.getElementById('myselect'),
selIndx = 0;
myselect.addEventListener('focus', function() {
selIndx = this.selectedIndex;
this.options[this.options.length - 1].selected = true;
}, false);
myselect.addEventListener('blur', function() {
this.selectedIndex = selIndx;
}, false);
myselect.addEventListener('change', function() {
selIndx = this.selectedIndex;
this.blur();
}, false);