JavaScript Form Validation
HTML form validation can be done by JavaScript.
Multiple Checkbox Validation
Validate Checkbox
Check at least one field should Checked
Display all selected checkbox value after submit
Example
<script>
function validateForm()
{
var transport =false;
for(i=0; i < document.myform.transport.length; i++)
{
if(document.myform.transport[i].checked == true)
{
transport = true;
break;
}
}
if(transport==false)
{
alert("Please select transport");
document.myform.transport[0].focus();
return false;
}
else{
var chk_arr = document.myform.transport;
for(var i = 0; i < chk_arr.length; i++){
if(chk_arr[i].checked) {
document.write(chk_arr[i].value+"
");
}
}
}
}
</script>
<form name="myform" onsubmit="return validateForm()" method="post">
<input type="checkbox" name="transport" id="transport" value="Car"/> Car
<input type="checkbox" name="transport" id="transport" value="Bus"/> Bus
<input type="checkbox" name="transport" id="transport" value="Bike"/> Bike
<input type="submit" value="Submit">
</form>