这是我简单的html表单代码
<form method="post" action=<?php echo base_url()."index.php/controller_bookplot2";?>
name="frmbooking" id="frmbooking">
<div class="marginbtm5">
<select name="name_title" class="dropdown" id="name_title" required>
<option value="Mr.">Mr.</option>
<option value="Miss">Miss</option>
<option value="Mrs">Mrs</option>
<option value="Dr.">Dr.</option>
</select>
<img src=<?php echo base_url()."images/rightmarked.gif";?> title="mandetory">
</div>
<div class="marginbtm5">
<input name="name" type="text" class="input validate_B" id="name" onfocus="if (this.value
== 'Full Name') {this.value=''}" onblur="if(this.value == '') {
this.value='Full Name'}" value="Full Name" required>
<img src=<?php echo base_url()."images/rightmarked.gif";?> title=" mandetory">
</div>
<div class="marginbtm5">
<input name="address" type="text" class="input validate_B" id="add" onfocus="if
(this.value == 'Address') {this.value=''}" onblur="if(this.value ==
'') { this.value='Address'}" value="Address" required>
<img src=<?php echo base_url()."images/rightmarked.gif";?> title=" mandetory">
</div>
<div class="marginbtm5">
<input name="email" type="text" class="input validate_B" id="email" onfocus="if
(this.value == 'Email') {this.value=''}" onblur="if(this.value ==
'') { this.value='Email'}" required value="Email" >
<img src=<?php echo base_url()."images/rightmarked.gif";?> title=" mandetory"
style="display:none;">
</div>
<div class="marginbtm5">
<input name="dob" type="text" class="input" value="Birth Date" required id="datepicker" >
<img src=<?php echo base_url()."images/rightmarked.gif";?> title=" mandetory">
</div>
<div class="marginbtm5">
<input name="mobno" type="text" class="input validate_B" maxlength="45" onfocus="if
(this.value == 'Mobile (10 digit mobile no. eg 9812345678)')
{this.value=''}" onblur="if(this.value == '') { this.value='Mobile
(10 digit mobile no. eg 9812345678)'}" value="Mobile (10 digit mobile no. eg
9812345678)" id="mob_no" pattern="[789][0-9]{9}" required
onkeyup="javascript:ValidateText(this)" >
</div>
<input name="btnSubmit" type="image" src=<?php echo base_url()."images/submit.jpg";?> value="Submit" onclick="return validate();">
</form>
我的表单中还有许多其他字段。但我只是在这里放了 5 个字段。当我单击提交时，它直接显示移动无字段的html5所需消息。它不会先验证姓名，地址，电子邮件，出生日期字段。那么我做错了什么？？
它不起作用，因为您正在给值属性删除值属性并尝试这样做
<form method="post" action=<?php echo base_url()."index.php/controller_bookplot2";?>
name="frmbooking" id="frmbooking">
<div class="marginbtm5">
<select name="name_title" class="dropdown" id="name_title" required>
<option value="">--Please select type</option>
<option value="Mr.">Mr.</option>
<option value="Miss">Miss</option>
<option value="Mrs">Mrs</option>
<option value="Dr.">Dr.</option>
</select>
<img src=<?php echo base_url()."images/rightmarked.gif";?> title="mandetory">
</div>
<div class="marginbtm5">
<input name="name" type="text" class="input validate_B" id="name" onfocus="if (this.value
== 'Full Name') {this.value=''}" onblur="if(this.value == '') {
this.value='Full Name'}" Placeholder="Full Name" required>
<img src=<?php echo base_url()."images/rightmarked.gif";?> title=" mandetory">
</div>
<div class="marginbtm5">
<input name="address" type="text" class="input validate_B" id="add" onfocus="if
(this.value == 'Address') {this.value=''}" onblur="if(this.value ==
'') { this.value='Address'}" Placeholder="Address" required>
<img src=<?php echo base_url()."images/rightmarked.gif";?> title=" mandetory">
</div>
<div class="marginbtm5">
<input name="email" type="text" class="input validate_B" id="email" onfocus="if
(this.value == 'Email') {this.value=''}" onblur="if(this.value ==
'') { this.value='Email'}" required Placeholder="Email" >
<img src=<?php echo base_url()."images/rightmarked.gif";?> title=" mandetory"
style="display:none;">
</div>
<div class="marginbtm5">
<input name="dob" type="text" class="input" Placeholder="Birth Date" required id="datepicker" >
<img src=<?php echo base_url()."images/rightmarked.gif";?> title=" mandetory">
</div>
<div class="marginbtm5">
<input name="mobno" type="text" class="input validate_B" maxlength="45" onfocus="if
(this.value == 'Mobile (10 digit mobile no. eg 9812345678)')
{this.value=''}" onblur="if(this.value == '') { this.value='Mobile
(10 digit mobile no. eg 9812345678)'}" value="Mobile (10 digit mobile no. eg
9812345678)" id="mob_no" pattern="[789][0-9]{9}" required
onkeyup="javascript:ValidateText(this)" >
</div>
<input name="btnSubmit" type="image" src=<?php echo base_url()."images/submit.jpg";?> value="Submit" onclick="return validate();">
</form>
如果向输入标签添加值，则它不会验证该文件，因为此文件已经具有值
无需随意 onfocus="if (this.value == 'Full Name') {this.value=''}" onblur="if(this.value == '') { this.value='Full Name'}" value="Full Name"
这可以通过 HTML 属性placeholder='Full Name'来实现