I have multiple fields with same id in HTML form and I want to hide them if the value of a particular field is 1 but it only hides the first field of that id all other fields are not hidden
<div class="form-group">
<label class="col-md-3 control-label" for="example-text-input" id="g">Days of week</label>
<div class="col-md-9">
<div class="checkbok">
<label for="example-checkbox1">
<input type="checkbox" id="g" name="gender" value="monday">Monday
</label>
</div>
<div class="checkbok">
<label for="example-checkbox1">
<input type="checkbox" id="g" name="gender" value="tuesday">Tuesday
</label>
</div>
<div class="checkbok">
<label for="example-checkbox1">
<input type="checkbox" id="g" name="gender" value="wednesday">Wednesday
</label>
</div>
<div class="checkbok">
<label for="example-checkbox1">
<input type="checkbox" id="g" name="gender" value="thursday">Thursday
</label>
</div>
<div class="checkbok">
<label for="example-checkbox1">
<input type="checkbox" id="g" name="gender" value="friday">Friday
</label>
</div>
<div class="checkbok">
<label for="example-checkbox1">
<input type="checkbox" id="g" name="gender" value="saturday">Saturday
</label>
</div>
<div class="checkbok">
<label for="example-checkbox1">
<input type="checkbox" id="g" name="gender" value="sunday"> Sunday
</label>
</div>
</div>
</div>
<div class="form-group">
<label class="col-md-3 control-label" for="example-text-input" id="g">Time</label>
<div class="col-md-3">
<select id="g" name="nod" class="form-control">
<?php
for($i=1;$i<=12;$i++){
echo"<option value='$i'>$i AM</option>";
}
for($i=1;$i<=12;$i++){
echo "<option value='12+$i'>$i PM</option>";
}?>
</select>
</div>
</div>
All the elements have the same id="g".Below is the javascript code
<script type="text/javascript">
var ele=document.getElementById("st").value;
if(ele==1)
document.getElementById("g").style.visibility = "hidden";
//else
//document.getElementById("g").style.visibility = "none";
</script>
But only the first element(ie the text days of week) gets hidden all others are shown.How do I hide all the others