我有以下脚本，它在选择下拉值时用数据填充表：
<script>
$(document).ready(function(){
$('#commodity_name').change(function (){
//picks the value of the selected commodity_name from the dropdown
option = $(this).find('option:selected').val();
html='';
htmlhead='';
// alert(option)
$.ajax({
type:"GET",
//gets data from the url specified based on the selected commodity_name in the dropdown
url:"<?php echo base_url();?>user_transactions/return_details/"+option,
dataType:"json",
success:function(data){
for(i=0;i<data.length;i++){
//Loops through the data to give out the data in a table format
//alert(data[i].transaction_type)
html += '<tr>\n\
<td><input type="text" id="commodity_name' + i + '" name="commodity_name[]" value="'+data[i].commodity_name+'"/></td>\n\
<td><input type="text" id="transaction_type' + i + '" name="transaction_type[]" value="'+data[i].transaction_type+'"/></td>\n\
<td><input type="text" id="total_quantity' + i + '" name="total_quantity[]" value="'+data[i].total_quantity+'"/></td>\n\
<td><input type="text" id="remarks' + i + '" name="remarks[]" value="'+data[i].remarks+'"/></td>\n\
<td><input type="text" id="unit_cost' + i + '" name="unit_cost[]" value="'+data[i].unit_cost+'"/></td>\n\
<td></td><td></td></tr> ';
}
htmlhead+='\n\
<th>Commodity Name</th>\n\
<th>Transaction Type</th> \n\
<th>Available Quantity</th> \n\
<th>Available Quantity</th> \n\
<th>Department</th>\n\
<th>Requestor Name</th>\n\
';
//alert(html);
//alert(htmlhead);
$('#thead').append(htmlhead);
$('#you').append(html);
//delegated submit handlers for the forms inside the table
$('#issue_1').on('click', function (e) {
e.preventDefault();
//read the form data ans submit it to someurl
$.post('<?php echo base_url()?>transactions/issues', $('#Issues_Form').serialize(), function () {
//success do something
alert("Success");
var url = "<?php echo base_url()?>transactions/view_request";
$(location).attr('href',url);
}).fail(function () {
//error do something
alert("Failed please try again later or contact the system Administrator");
})
})
},
error:function(data){
}
})
});
});
</script>
当我在下拉列表中选择下一个商品名称时，如何清除已附加的 html 表中的数据，我只获得从下拉列表中选择的新选择返回的数据。