我正在做这个项目，我用HTML编写了一个注册表单并通过javascript“简单地”验证了它。通过'简单'我的意思是我只是确保输入字段不为空。 现在，问题是什么？一切正常，直到有人从大学列表中选择“其他”选项（id = cname）并出现一个新的输入框（其中id = cname1）。现在，如果有人将输入框留空，它会返回一条警告，上面写着“学院名称不能为空！”，但是他无法点击提交按钮。我仔细检查了语法，一切似乎都很好。这是我的javascript代码：
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：缩小的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>
<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>
由于
答案 0 :(得分：2)
问题是你没有将你的if语句包装在大括号中。
令人讨厌的片段：
// input v[0]...v[n-1] is a vector of integers already filled.
// output : stack s
stack<int> s;
for(auto x: v){
while(!s.empty() && x > s.top()) s.pop();
s.push(x);
}
这与写作相同：
var cname1=document.getElementById("cname1").value;
if(cname1==="")
alert("College Name can't be empty");
return false;
这意味着一旦达到此值，您将始终返回var cname1=document.getElementById("cname1").value;
if(cname1==="") {
alert("College Name can't be empty");
}
return false;
。如果用户能够做到这一点，这将始终阻止表单提交。
修复很简单：
false出于这个原因，许多人认为在编写JavaScript时始终包含大括号是最佳做法。