Tab键不会't继续chrome/IE11中的表单字段

我有一个表单，当我按下tab键时，它会在文本框中移动，但当它到达密码字段时，它不会向前或向后移动。Firefox没有显示这个问题，但chrome和IE11显示了这个问题。

<tr>
      <td  style="text-align:left"><label for="name"> Name<font color="red">*</font> </label></td>
      <td ><input type="text" id="doctorName" name="doc_name" placeholder="Name" onblur="allLetter(document.registration.doc_name)"  required />
      </td><td><img src="images2/image.png" class="masterTooltip" title="eg. Mr|Ms|Dr|Smt  Last First Middle name"></td><td style="text-align:left"><i name="nameb"style='color:red' id='docnm' ></i></td>
      </tr>
      <tr>
      <td style="text-align:left"> <label for="email" > Email </label></td>
      <td  ><input type="text" id="doctorEmail" name="doc_email" onblur="myfun()" placeholder="Email"  required /></td><td><img src="images2/image.png" class="masterTooltip" title="Enter valid email for eg. abcd@example.com"></td>
      <td style="text-align:left"> <i style='color:red' id='email' ></i></td>
      </tr>
      <tr>
      <td style="text-align:left"> <label for="uname" >User Name<font color="red">*</font></label></td>
      <td ><input type="text" id="userName" name="username" onblur="allLetter_username(document.registration.username)" placeholder="User Name"  required />
      </td><td><img src="images2/image.png" class="masterTooltip" title="UserName contains a-z, A-Z, 0-9, _"></td><td style="text-align:left"><i name="nameb"style='color:red' id='usernm' ></i></td>
      </tr>
      <tr>
      <td style="text-align:left"> <label for="password" >Password<font color="red">*</font> </label></td>
      <td ><input type="password" id="doctorPassword" name="doc_password" onblur="passid_validation(7,20)" placeholder="Password"   /><td></td>
      </td><td style="text-align:left"> <i style='color:red' id='pass' ></i></td>
      </tr>

// This function will validate Password.
function passid_validation(mx,my)
{
    var passid = document.registration.doc_password;
    var passid_len = passid.value.length;
    if (passid_len == 0 ||passid_len >= my || passid_len < mx)
    {
        document.getElementById('pass').innerHTML="Password length must     be 7 to 20";
        passid.focus();
        return false;
    }
    else
    {
        document.getElementById('pass').innerHTML='';
        return true;
    }
}