function code(f){

var chr = escape(f.keyword.value);
var chr_lng = chr.length;

if (chr_lng == 0){
	alert("キーワードを入力してください。");
	return false;
}

for (i=0 ;i < chr.length ;i++){
	if (chr.substring(i,i+1) == "%"){
		if (chr.substring(i+1,i+3) == "81"
		|| chr.substring(i+1,i+3) == "82"
		|| chr.substring(i+1,i+3) == "83"
		|| chr.substring(i+1,i+3) == "84"
		|| chr.substring(i+1,i+3) == "85"
		|| chr.substring(i+1,i+3) == "86"
		|| chr.substring(i+1,i+3) == "87"
		|| chr.substring(i+1,i+3) == "88"
		|| chr.substring(i+1,i+3) == "89"
		|| chr.substring(i+1,i+3) == "8A"
		|| chr.substring(i+1,i+3) == "8B"
		|| chr.substring(i+1,i+3) == "8C"
		|| chr.substring(i+1,i+3) == "8D"
		|| chr.substring(i+1,i+3) == "8E"
		|| chr.substring(i+1,i+3) == "8F"
		|| chr.substring(i+1,i+3) == "90"
		|| chr.substring(i+1,i+3) == "91"
		|| chr.substring(i+1,i+3) == "92"
		|| chr.substring(i+1,i+3) == "93"
		|| chr.substring(i+1,i+3) == "94"
		|| chr.substring(i+1,i+3) == "95"
		|| chr.substring(i+1,i+3) == "96"
		|| chr.substring(i+1,i+3) == "97"
		|| chr.substring(i+1,i+3) == "98"
		|| chr.substring(i+1,i+3) == "99"
		|| chr.substring(i+1,i+3) == "9A"
		|| chr.substring(i+1,i+3) == "9B"
		|| chr.substring(i+1,i+3) == "9C"
		|| chr.substring(i+1,i+3) == "9D"
		|| chr.substring(i+1,i+3) == "9E"
		|| chr.substring(i+1,i+3) == "9F"
		){
			if (chr.substring(i+3,i+4) == "%"){
				i = i + 5;
			}else{
				i = i + 3;
			}
		}else{
			if (chr.substring(i+1,i+3) == "3B"
			|| chr.substring(i+1,i+3) == "3F"
			|| chr.substring(i+1,i+3) == "5B"
			|| chr.substring(i+1,i+3) == "5C"
			|| chr.substring(i+1,i+3) == "5E"
			|| chr.substring(i+1,i+3) == "60"
			|| chr.substring(i+1,i+3) == "7B"
			|| chr.substring(i+1,i+3) == "7E"
			){
				alert("このキーワードでは検索できません。");
				return false;
			}else{
				i = i + 2;
			}
		}
	}else{
		if (chr.substring(i,i+1) == "*"
		|| chr.substring(i,i+1) == "."
		|| chr.substring(i,i+1) == "+"
		){
			alert("このキーワードでは検索できません。");
			return false;
		}
	}
}

if (chr.substring(chr.length-2,chr.length) == "24"){
	alert("このキーワードでは検索できません。");
	return false;
}

//return false;
return true;
}