$(function() {
	  $(document).on("keypress", "input:not(.allow_submit)", function(event) {
	    return event.which !== 13;
	  });
	});

var chkFlg = 0;
$("form").submit(function() {
	if(chkFlg == 1){
		return false;
	}else{
		chkFlg =1;
		return true;
	}
});