Jquery Onchange事件未被触发

Question

I have an onChange event, but upon change it is not being triggered. I have verified I am calling the fields correctly.

    $("#SRIEquipmentDDL").change(function() {
    if ($(this).val() == "3") {
        $("#SRILift").show();
    } else {
        $("#SRILift").hide();
    }
});

<div id="SRIEquipment">
            <div class="TextField">Equipment:</div>
            <div class="InputField">
                <select name="SRIEquipmentDDL" id="SRIEquipmentDDL" class="DropDownField">
                    <option value="0" <?php if ($_POST['SRIEquipmentDDL'] == "0") {echo "selected='selected'";} ?> >Select Chair Type</option>
                    <option value="1" <?php if ($_POST['SRIEquipmentDDL'] == "1") {echo "selected='selected'";} ?> >Manual Wheelchair</option>
                    <option value="2" <?php if ($_POST['SRIEquipmentDDL'] == "2") {echo "selected='selected'";} ?>>Power Wheelchair</option>
                    <option value="3" <?php if ($_POST['SRIEquipmentDDL'] == "3") {echo "selected='selected'";} ?>>Lift Chair</option>
                    <option value="4" <?php if ($_POST['SRIEquipmentDDL'] == "4") {echo "selected='selected'";} ?>>Scooter</option>
                    <option value="5" <?php if ($_POST['SRIEquipmentDDL'] == "5") {echo "selected='selected'";} ?>>Lifts</option>
                    <option value="6" <?php if ($_POST['SRIEquipmentDDL'] == "6") {echo "selected='selected'";} ?>>CPM</option>
                    <option value="8" <?php if ($_POST['SRIEquipmentDDL'] == "7") {echo "selected='selected'";} ?>>Walker</option>                          
                    <option value="9" <?php if ($_POST['SRIEquipmentDDL'] == "8") {echo "selected='selected'";} ?>>Other</option>
                </select>
            </div>
        </div>
        <div id="SRILift">
            <div class="TextField">Lift Type:</div>
            <div class="InputField">
                <select name="SRILiftTypeDDL" id="SRILiftTypeDDL" class="DropDownField">
                    <option value="0" <?php if ($_POST['SRILiftTypeDDL'] == "0") {echo "selected='selected'";} ?> >Select Lift Type</option>
                    <option value="1" <?php if ($_POST['SRILiftTypeDDL'] == "1") {echo "selected='selected'";} ?> >Stair Lift</option>
                    <option value="2" <?php if ($_POST['SRILiftTypeDDL'] == "2") {echo "selected='selected'";} ?>>Porch Lift</option>
                    <option value="3" <?php if ($_POST['SRILiftTypeDDL'] == "3") {echo "selected='selected'";} ?>>Outside Vehicle Lift</option>
                    <option value="4" <?php if ($_POST['SRILiftTypeDDL'] == "4") {echo "selected='selected'";} ?>>Inside Vehicle Lift</option>
                    <option value="5" <?php if ($_POST['SRILiftTypeDDL'] == "5") {echo "selected='selected'";} ?>>Ceiling Lift</option>                     
                    <option value="6" <?php if ($_POST['SRILiftTypeDDL'] == "6") {echo "selected='selected'";} ?>>Other</option>
                </select>
            </div>
        </div>

Answer 1

Try something like this:

 $('#yourSelectId').change(function() {
    var selectedVal = $('#yourSelectId option:selected').attr('value');
});

make sure you code is inside a ready function - http://api.jquery.com/ready/ or it is after the HTML that create the select