var kakusu_o_f = '#f00';
var kakusu_o_b = '#ccc';
var kakusu_c_f = '#999';
var kakusu_c_b = '#999';
var kakusus = document.getElementsByTagName('span');
for (var i = 0;i < kakusus.length;i++) {
  if (kakusus[i].getAttribute('kakusu') != 'on') {continue;}
  kakusus[i].style.background = kakusu_c_b;
  kakusus[i].style.color      = kakusu_c_f;
kakusus[i].show = false;
  kakusus[i].onclick = function onlick (event) {
	if(this.show==false){
    	this.style.background = kakusu_o_b;
    	this.style.color      = kakusu_o_f;
	}else{
    	this.style.background = kakusu_c_b;
    	this.style.color      = kakusu_c_f;
	}
	this.show =!this.show;
  }
}