called this function onchange
event of radio button, if dpcp, state is true
otherwise false
function state_change(state){
if(state){
$('#ip').removeAttr("data-validation-engine");
$('#gateway').removeAttr("data-validation-engine");
$('#dns').removeAttr("data-validation-engine");
} else{
$('#ip').attr("data-validation-engine","validate[required,custom[ipv4]]");
$('#gateway').attr("data-validation-engine","validate[required,custom[ipv4]]");
$('#dns').attr("data-validation-engine","validate[required,custom[ipv4]]");
}
}