js 自定义的联动下拉框_javascript技巧

$containerDivText.mousedown(function() {
setTimeout(
function() {
if ($newUl[0].style.display == 'block') {
$newUl.hide();
positionHideFix();
return false;
}
$containerDiv.focus();
//show list
$newUl.slideDown(100);
positionFix();
//when keys are pressed
document.onkeydown = function(e) {
if (e == null) { // ie
var keycode = event.keyCode;
} else { // everything else
var keycode = e.which;
}
//enter key or esc key pressed, hide list
if (keycode == 13 || keycode == 27) {
$newUl.hide();
positionHideFix();
return false;
}
}
}, 1);
//the function settimeout is used for ie6, because if you click the element where you hava focused on the element,
//ie6 would think you click it twice(2010-2-4)
});

if (!opts.callbackfn) {
$newLi.click(function(e) {
var $clickedLi = jQuery(e.target),
text = $clickedLi.text();
//update counter
currentIndex = $newLi.index($clickedLi);
//remove all hilites, then add hilite to selected item
$newLi.removeClass('hiLite');
$clickedLi.addClass('hiLite');
setSelectText(text);
$newUl.hide();
$containerDiv.css('position', 'static'); //ie
});
} else {
$newLi.click(function(e) {
var $clickedLi = jQuery(e.target),
text = $clickedLi.text();
//update counter
currentIndex = $newLi.index($clickedLi);
//remove all hilites, then add hilite to selected item
$newLi.removeClass('hiLite');
$clickedLi.addClass('hiLite');
setSelectText(text);
$newUl.hide();
$containerDiv.css('position', 'static'); //ie
(opts.callbackfn)(this.value);
});
} //param callbackfn means you can define a event function from every li in the ul;(2010-2-4)