title: javascript radio button validate
body: <p>hey guys i just try to do some validate for my javascript radio button, but is not work. every time i click submit button it just nothing happened.below is the code.
  <br><br><br>HTML part             </p>
  
  <pre><code>   &lt;form name="FirstPizza"&gt;
           &lt;td&gt;
               Style:
                  &lt;br/&gt;
              &lt;input type="radio" name="style"/&gt;
              Thin Crust
                  &lt;br /&gt;
              &lt;input type="radio" name="style" /&gt;
              Deep Dish
                  &lt;br /&gt;
              &lt;input type="radio" name="style" /&gt;
              Sicilian
          &lt;/td&gt;
     &lt;/form&gt;
  </code></pre>
  
  <p>Javascript:</p>
  
  <pre><code>function submitForm(){
          if((!form.style[0].checked)  &amp;&amp; (!form.style[1].checked) &amp;&amp; (!form.style[2].checked))
               {
             window.alert("You must have a  style")
               }
  </code></pre>
  
  <p>i should come with a box but nothing happen. Do i miss something?</p>