this.randomtip_header = function(){
	var length = $("#header_illustration p").length;
	var ran = Math.floor(Math.random()*length) + 1;
	$("#header_illustration p:nth-child(" + ran + ")").show();
};

this.randomtip_why = function(){
	var length = $("#why_illustration a").length;
	var ran = Math.floor(Math.random()*length) + 1;
	$("#why_illustration a:nth-child(" + ran + ")").show();
};

this.randomtip_action = function(){
	var length = $("#action_illustration span").length;
	var ran = Math.floor(Math.random()*length) + 1;
	$("#action_illustration span:nth-child(" + ran + ")").show();
};

$(document).ready(function(){	
  randomtip_header();
  randomtip_why();
  randomtip_action();
});