如何使用Java脚本验证单选按钮和下拉列表？

Question

i have field gender in the form. if user doesn't select the radio button, i must show a message "please select your gender". also the user must select age group..

Form:

<label>Gender<br />
</label>
<label>Male</label><input id="male" type="radio" name="gender" class="box" style="border:solid 3px #333333" value="male" />
<label>female</label><input id="female" type="radio" name="gender" value="female"><br /><br />
<label>Age </label>
<select name="age">
<option>Select</option>
  <option value="Below 16">Below 16/option>
  <option value="16-20">16-20</option>
  <option value="21-25">21-25</option>
  <option value="26-30">26-30</option>
  <option value="31-35">31-35</option>
  <option value="Above 35">Above 35</option>
</select>
<input type="submit" value=" Register " style="border:solid 2px #333333"/>

Java Script

<script type="text/javascript">
function validateForm()
{
if (document.getElementById("male").checked=false && document.getElementById("female").checked=false)
{
     alert("Please select Gender");
  return false;
}
}

user must select gender and age.. otherwise he is not allowed to register. how to do it?

Answer 1

Yes, You really need google before the post of any question. There is lots of things which you are missing.

Check working example: Demo

Jquery code:

$(function(){
    $("#register").on('click', function(){
            console.log($("select[name=age] option:selected"));
        if ($('input[name="gender"]:checked').length== 0){
            alert('select gender');
            return false;
        }

        if($("select[name=age] option:selected").val()==""){
            alert('select age');
            return false;   
        }
        alert('form submit');
        return false;
    });
});

I just added id in submit button:

<input type="submit" value=" Register" id="register" style="border:solid 2px #333333"/>

Answer 2

if ((document.getElementById("lawn1").checked == false) &&     
    (document.getElementById("lawn2").checked == false))