我尝试在JavaScript中创建验证码，但遇到了问题。我希望验证码随机显示，其中一个声明的图像，然后验证用户输入对图像上的文本。到目前为止，我有下面的代码，它没有显示任何东西：

<script type="text/javascript"> 
    var "<img src="images/ci0.jpg" />" = 56777;
    var "<img src="images/ci1.jpg" />" = 67646;      
    var "<img src="images/ici2.jpg" />" = 77666;           
 var code = ci0, ci1, ci2;
 document.getElementById("txtCaptcha").value = code;
  document.getElementById("txtCaptchaDiv").innerHTML = code;
  </script>

超文本标记语言

<div id="left">
        
         <label for="code">Enter code next  <span id="txtCaptchaDiv" style="color:#F00"></span><br />
<!-- this is where the script will place the generated code -->
          <input type="hidden" id="txtCaptcha" /></label>
          
          </div><!-- End Left -->
        <div id="righty">
        <span id="spryconfirm1">
        <label>
          <input type="text" name="checker" id="checker" />
        </label>
        <span class="confirmRequiredMsg">You must enter the Code.</span><span class="confirmInvalidMsg">The values don't match.</span></span>
        
        </div><!-- End righty -->  
       
       
       
       </div>