我在验证用户是否提交默认选择选项时遇到问题这是一个示例表单：
<form action="/shopping-cart" method="post" class="eshop addtocart" id="eshopprod7751562209795">
<fieldset>
<span class="eshop eselect"><label for="exopt1001562209795">Choose Size and Type… </label><br>
<select class="cartselectclass" id="exopt1001562209795" name="optset[0][id]"><option value="" selected="selected">Choose Option...</option>
<option value="129">8" x 10" – Print + $9.95</option>
<option value="130">11" x 14" – Print + $19.95</option>
<option value="131">16" x 20" – Canvas + $299.00</option>
</select>
</span>
<label for="qty7751562209795" class="qty"><abbr title="Quantity">Qty</abbr>:</label>
<input type="text" value="1" id="qty7751562209795" maxlength="3" size="3" name="qty" class="iqty">
<input class="button mybutton" value="Add to Cart" title="Add selected item to your shopping basket" type="submit">
</fieldset>
</form>
这是用于验证选择选项的 jquery：我正在尝试的是，如果用户不小心点击了添加到购物车，如果他们没有选择任何选项，默认情况下选择“选择选项”，他们会收到警报。
jQuery(document).ready(function($){
$('select.cartselectclass option:first-child').remove();
$('.cartselectclass').prepend('<option value="" selected="selected">Choose Option...</option>').val('');
$('.mybutton').click(function(){
if ($('.cartselectclass').val()=='')
{
alert('Please choose at least one option.');
return false;
}
})
$('.addtocart').submit(function(){
var Id =$(this).attr("id");
var data = {action: 'eshop_special_action',post:$('#'+Id).serialize() };
$.post(""+eshopCartParams.adminajax, data,
function(response){
$('#'+Id +" .eshopajax").insertAfter(this).fadeIn(100).html(response).fadeOut(3000);
setTimeout (cleareshopCart,1000);
setTimeout (doeshopRequest,750);
setTimeout (cleareshopRequest,3000);
});
function doeshopRequest(){
var tdata = {action: 'eshop_cart'};
$.post(""+eshopCartParams.adminajax, tdata,
function(response){
$(".ajaxcart").insertAfter(this).fadeOut(50).html(response).fadeIn(700);
});
}
function cleareshopRequest(){
$(".eshopajax").empty();
}
function cleareshopCart(){
$(".ajaxcart").insertAfter();
}
return false;
});
});