How do I Required text box if radio button selected on form submission using jquery?

问题

How do I require the second text box have some text in it on the submission of this form if the second radio button is selected?

<form action="" method="post" id="search_form" name="search_form">
                <div id="inquryValue-form-item" class="form-item">
                    <div class="form-radio display-inline">
                        <input type="radio" class="required" value="" checked="checked" id="inquryValue" name="search_value">
                    </div>
                    <div class="field-label-45-percent display-inline">
                        <label>
                            Inquiry ID
                        </label>
                    </div>
                    <div id="fepUserIDValueWrapper" class="form-radio display-inline">
                        <input type="radio" class="required" value="" id="fepUserIDValue" name="search_value">
                    </div>
                    <div class="field-label-45-percent display-inline">
                        <label id="fepUserIDValueLabel" for="fepUserIDValue">
                            FEPDirect User ID
                        </label>
                    </div>
                    <div id="inquiry_dateLabelWrapper" class="field-label-45-percent display-inline">
                        <label id="inquiry_dateLabel" for="inquiry_date">
                            Inquiry Date
                        </label>
                    </div>
                </div>
                <div id="fepUserIDValue-form-item" class="form-item">
                    <div id="Search_valueWrapper" class="form-textfield">
                        <input type="text" class="required" value="" id="search_value" name="search_value">
                    </div>
                    <div id="Inquiry_dateWrapper" class="form-textfield">
                        <input type="text" name="inquiry_date" id="inquiry_date" class="date-picker hasDatepicker">
                        <div id="search_value_labelWrapper" class="field-label">
                            <div class="field-description">
                                <span title="This field is required if entering a User ID" class="required">*</span>
                                This field is required if entering an User ID
                            </div>
                        </div>
                    </div>
                    <input type="button" id="search_inquiry-submit" class="neutral" value="Search">
                </div>
                </form>

回答1:

Try this:

$('#search_form').submit(function() {
    if($('#fepUserIDValue').attr("checked") == "checked" && $('#inquiry_date').val() == '') {
       alert('Required field missing');
       return false;
    }
});

回答2:

Look at this question: jQuery.Validate Conditional Validation RadioButton and DropDownList

来源：https://stackoverflow.com/questions/6525103/how-do-i-required-text-box-if-radio-button-selected-on-form-submission-using-jqu