var red = "<font color='red'>";
var green = "<font color='green'>";
var colend = "</font>";

var email_exist = false;
var illegual_email = false;
var illegual_serial = false;

//	初期化
function update_difficulty(index){

	option = document.form1.elements["option[depth_sel]"];
	switch(document.form1.elements["option[difficulty_sel]"].selectedIndex){
		case 0:
			option.length = 2;
			break;
		case 1:
			option.length = 3;
			break;
		default:
			option.length = 4;
			break;
	}
	options = new Array("全て", "全30層", "全50層", "全100層");
	for(i = 0; i < 4; i++){
		option.options[i].text = options[i];
		option.options[i].value = i;
	}
	document.form1.elements["option[depth_sel]"].selectedIndex = index; 
}