Javascript驗證錯誤，無法提交表格

我正在做這個項目，我在HTML中做了一個註冊表單，並通過javascript'簡單'驗證它。通過'簡單'我的意思是我只是確保輸入字段不是空的。現在，這有什麼問題？一切工作正常，直到有人從大學列表（id = cname）中選擇「others」選項，並且會出現一個新的輸入框（其中id = cname1）。現在，如果有人將輸入框留空，它將返回一個警告，提示「大學名稱不能爲空！」，但他無法點擊提交按鈕。我仔細檢查了語法，一切似乎都很好。這裏是我的javascript代碼：Javascript驗證錯誤，無法提交表格

  function validate(){ 
 
       var name=document.getElementById("name").value; 
 
       if(name===""){ 
 
         document.getElementById("ename").innerHTML="Please Enter a Name"; 
 
         return false; 
 
       }else{ 
 
        var mail=document.getElementById("mail").value; 
 
        if(mail===""){ 
 
         document.getElementById("email").innerHTML="Please Enter an Email"; 
 
         return false; 
 
        }else{ 
 
        var num=document.getElementById("num").value; 
 
        if(num===""){ 
 
         document.getElementById("enum").innerHTML="Please Enter Phone number"; 
 
         return false; 
 
        }else{ 
 
         var batch=document.getElementById("batch").value; 
 
         if(batch===""){ 
 
          document.getElementById("ebatch").innerHTML="Please Enter a Batch"; 
 
          return false; 
 
         } 
 
         else{ 
 
          var cname=document.getElementById("cname").value; 
 
          if(cname===""){ 
 
          document.getElementById("ecname").innerHTML="Please Enter a College Name"; 
 
          return false; 
 
          }else if(cname==="others"){ 
 
           var cname1=document.getElementById("cname1").value; 
 
           if(cname1==="") 
 
            alert("College Name can't be empty"); 
 
           return false; 
 
          }else{ 
 
           var activity=document.getElementById("activity").value; 
 
           if(activity===""){ 
 
           document.getElementById("eactivity").innerHTML="Please Enter a Activity Name"; 
 
           return false; 
 
           }else{ 
 
            return true; 
 
           } 
 
          } 
 
         } 
 
        } 
 
       } 
 
      } 
 
     }

更新2：收縮編輯HTML

<tbody> 
 
      <tr> 
 
       <td>Name</td> 
 
       <td><input class="css-input" type="text" id="name" name="name" placeholder="Enter your name"></td> 
 
       <td><p id="ename"></p></td> 
 
      </tr> 
 
      <tr> 
 
       <td>Email</td> 
 
       <td><input class="css-input" type="text" id="mail" name="mail" placeholder="Enter your Email Id"></td> 
 
       <td><p id="email"></p></td> 
 
      </tr> 
 
      <tr> 
 
       <td>Phone</td> 
 
       <td><input class="css-input" type="tel" id="num" name="num" Placeholder="Phone Number"></td> 
 
       <td><p id="enum"></p></td> 
 
      </tr> 
 
      <tr> 
 
       <td>Course</td> 
 
       <td> 
 
        <select class="css-input" name="course" id="course"> 
 
         <option value="mbbs" >MBBS</option> 
 
         <option value="bds" selected="selected" >BDS</option> 
 
        </select> 
 
       </td> 
 
      </tr> 
 
      
 
      <tr> 
 
       <td>Batch</td> 
 
       <td> 
 
        <select class="css-input" name="batch" id="batch" > 
 
         <option value="10">2010</option> 
 
         <option value="11">2011</option> 
 
         <option value="12">2012</option> 
 
         <option value="13">2013</option> 
 
         <option value="14">2014</option> 
 
         <option value="15">2015</option> 
 
        </select> 
 
       </td> 
 
       <td><p id="ebatch"></p></td> 
 
      </tr> 
 
      <tr> 
 
       <td>WorkShop</td> 
 
       <td id="first"> 
 
        <select class="css-input" name="workshop1"> 
 
         <option value="dentistry">Dentistry</option> 
 
         <option value="communicationsoftskill">Communication and Soft Skills</option> 
 
         <option value="research">Going about Research</option> 
 
         <option value="None">None</option> 
 
        </select> 
 
         
 
       </td><td id="third"> 
 
        <select class="css-input" name="workshop3"> 
 
         
 
         <option value="communicationsoftskill">Communication and Soft Skills</option> 
 
         <option value="research">Going about Research</option> 
 
         <option value="None">None</option> 
 
        </select> 
 
         
 
       </td> 
 
       <td class="second" id="second"> 
 
        <select class="css-input" name="workshop2"> 
 
         <option value="surgery">Surgical</option> 
 
         <option value="radiodiagnostic">Radiodiagnostics</option> 
 
         <option value="comandsoftskill">communication and soft skills</option> 
 
         <option value="emercriticalcare">emergency and critical care</option> 
 
         <option value="research">going about research</option> 
 
         <option value="None">None</option> 
 
        </select> 
 
       </td> 
 
      </tr> 
 
      
 
      <tr> 
 
       <td>College name</td> 
 
       <td> 
 
        <select class="css-input" name="cname" id="cname"> 
 
         <option value="PGIMS, Rohtak">PGIMS, Rohtak</option> 
 
         <option value="Swami Devi Dayal Dental College , Panchkula">Swami Devi Dayal Dental College , Panchkula</option> 
 
         <option value="BRS Instititute of Medical Sciences Dental College and Hospital , Sultanpur , Panchkula">BRS Instititute of Medical Sciences Dental College and Hospital , Sultanpur , Panchkula</option> 
 
         <option value="Kothiwal Dental and Research Centre , Moradabad">Kothiwal Dental and Research Centre , Moradabad</option> 
 
         <option value="Teerthankar Mahavir Dental College , Moradabad">Teerthankar Mahavir Dental College , Moradabad</option> 
 
         <option value="Teerthankar Mahavir Medical College and Research Center , Moradabad">Teerthankar Mahavir Medical College and Research Center , Moradabad</option> 
 
         <option value="ESIC , Faridabad">ESIC , Faridabad</option> 
 
         <option value="Maharishi Markandeshwar College of Dental Sciences , Mullana , Ambala">Maharishi Markandeshwar College of Dental Sciences , Mullana , Ambala</option> 
 
         <option value="JN Kapoor DAV Centenary Dental College and Hospital , Yamunanagar">JN Kapoor DAV Centenary Dental College and Hospital , Yamunanagar</option> 
 
         <option value="Jan Nayak Ch. Devi Lal Dental College , Sirsa">Jan Nayak Ch. Devi Lal Dental College , Sirsa</option> 
 
         <option value="Manav Rachna Dental College , Faridabad">Manav Rachna Dental College , Faridabad</option> 
 
         <option value="SGT Dental College , Gurgaon">SGT Dental College , Gurgaon</option> 
 
         <option value="PDM Dental College and Research Institute , Bahadurgarh">PDM Dental College and Research Institute , Bahadurgarh</option> 
 
         <option value="Sudha Rustagi College of Dental Sciences And Research , Faridabad">Sudha Rustagi College of Dental Sciences And Research , Faridabad</option> 
 
         <option value="Dr. Harvansh Singh Gudge Institute of Dental Sciences and Hospital , Chandigarh">Dr. Harvansh Singh Gudge Institute of Dental Sciences and Hospital , Chandigarh</option> 
 
         <option value="Swami Devi Dayal Hospital and Dental College, Barwala">Swami Devi Dayal Hospital and Dental College, Barwala</option> 
 
         <option value="Yamuna Institute of Dental Sciences And Research , Yamunanagar">Yamuna Institute of Dental Sciences And Research , Yamunanagar</option> 
 
         <option value="Lala Lajpat Rai Memorial Medical College , Meerut , Uttar Pradesh">Lala Lajpat Rai Memorial Medical College , Meerut , Uttar Pradesh</option> 
 
         <option value="Dayanand Medical College , Ludhiana">Dayanand Medical College , Ludhiana</option> 
 
         <option value="CMC , Ludhiana">CMC , Ludhiana</option> 
 
         <option value="GMC , Chandigarh">GMC , Chandigarh</option> 
 
         <option value="AFMC , Pune">AFMC , Pune</option> 
 
         <option value="ACMS , Delhi Cantt.">ACMS , Delhi Cantt.</option> 
 
         <option value="UCMS , New Delhi">UCMS , New Delhi</option> 
 
         <option value="VMMC , New Delhi">VMMC , New Delhi</option> 
 
         <option value="Sawai Man Singh Medical College , Jaipur">Sawai Man Singh Medical College , Jaipur</option> 
 
         <option value="IGMC , Shimla ">IGMC , Shimla </option> 
 
         <option value="Gold Institute of Medical Sciences and Research , Ballabhgarh ">Gold Institute of Medical Sciences and Research , Ballabhgarh </option> 
 
         <option value="28. Maharshi Markandeshwar Institute of Medical Sciences and Research , Mullana , Ambala">Maharshi Markandeshwar Institute of Medical Sciences and Research , Mullana , Ambala</option> 
 
         <option value="SGT Medical College , Budhera , Gurgaon">SGT Medical College , Budhera , Gurgaon</option> 
 
         <option value="Maharaja Agarsen Medical College , Agroha , Hisar">Maharaja Agarsen Medical College , Agroha , Hisar</option> 
 
         <option value="Shaheed Hasan Khan Mewati GMC , Mewat ">Shaheed Hasan Khan Mewati GMC , Mewat </option> 
 
         <option value="BPS GMC for women , Khanpur">BPS GMC for women , Khanpur32. BPS GMC for women , Khanpur</option> 
 
         <option value="GMC , Patiala ">GMC , Patiala </option> 
 
         <option value="others">others</option> 
 
        </select> 
 
       </td> 
 
       <td><input class="css-input" type="text" name="cname1" id="cname1" placeholder="enter Your college name"></td> 
 
\t <input type="hidden" value="1" id="flg" name="flg"> 
 
       <td><p id="ecname"></p></td> 
 
      </tr> 
 
      
 
      <tr> 
 
       <td>Accomodation</td> 
 
       <td> 
 
        <select class="css-input" id="accom" name="accom"> 
 
         <option value="yes" selected="selected">YES</option> 
 
         <option value="no">NO</option> 
 
        </select> 
 
       </td> 
 
      </tr> 
 
      <tr> 
 
       <td><input class="css-input" type="reset"></td> 
 
       <td><input style="cursor: pointer;" class="css-input" type="submit" ></td> 
 
      </tr> 
 
     </tbody>

感謝

來源

2015-10-14 Vivek

看起來像你的代碼段缺少html –

你試過使用調試器嗎？也許[Chrome開發工具]（https://developer.chrome.com/devtools）？ –

有大量的代碼不是實際問題的一部分。你可以用只有輸入的問題做一個測試用例，只有基本的JavaScript？這個問題似乎是由其他JavaScript引起的，但代碼有點難以追查。二，Javascript驗證必不可少意味着不驗證。用戶可以通過腳本攔截器無意中繞過它們，而不是。你將不得不編寫一些奇怪的情況來處理糟糕的輸入，所以首先通過服務器端代碼來實現，然後通過JS添加快速和簡約的檢查來減少服務器命中。 – Nelson

問題是你沒有把你的if語句包裝在大括號中。

有問題的片段：

var cname1=document.getElementById("cname1").value; 
if(cname1==="") 
    alert("College Name can't be empty"); 
return false;

這是相同的文字：

var cname1=document.getElementById("cname1").value; 
if(cname1==="") { 
    alert("College Name can't be empty"); 
} 
return false;

這意味着你將總是返回false，一旦你得到這個值。這將始終阻止提交表單提供用戶得到這一點。

修復的方法是直截了當：

var cname1=document.getElementById("cname1").value; 
if(cname1==="") { 
    alert("College Name can't be empty"); 
    return false; 
}

出於這個原因，許多人認爲它最佳實踐編寫JavaScript時，始終包括括號。

來源

2015-10-14 03:17:07 jacobangel

好的。自己很難找到這些問題，因爲在思想上你認爲你把它放在了大括號中...... :) – Nelson

謝謝@jacobangel :)我並沒有期待這個錯誤，因爲尼爾森說。對不起尼爾森，你是對的:) PS：客戶端還沒有注意到這一點:) – Vivek

Javascript驗證錯誤，無法提交表格

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