function deleteTown(){
	var townElement = document.getElementById('town');
	if(townElement.length > 0){
		var len = townElement.length;
		for(i = 0; i < len; i++){
			townElement.options[len - i - 1] = null;
		}
	}
}

function deleteSchool(){
	var schoolElement = document.getElementById('name');
	if(schoolElement.length > 0){
		var len = schoolElement.length;
		for(i = 0; i < len; i++){
			schoolElement.options[len - i - 1] = null;
		}
	}
}

function changeSite(id){
	var step = id - 1;
	var s_info = school_info[step];
	var pref_info = new Array(s_info.length);
	var prefElement = document.getElementById('pref');
	if(prefElement.length > 0){
		var len = prefElement.length;
		for(i = 0; i < len; i++){
			prefElement.options[len - i - 1] = null;
		}
	}
	var cnt = 0;
	prefElement.options[cnt] = new Option("選択してください", "");
	cnt++;
	if(s_info.length > 0){
		for(i = 0; i < s_info.length; i++){
			var info = s_info[i];
			if(pref_info[info[2]] == null){
				pref_info[info[2]] = info[2];
				prefElement.options[cnt] = new Option(info[2], info[2]);
				cnt++;
			}
		}
	}
	deleteTown();
	var townElement = document.getElementById('town');
	townElement.options[0] = new Option("選択してください", "");
	cnt = 1;
	if(s_info.length > 0){
		var town_info = new Array(s_info.length);
		for(i = 0; i < s_info.length; i++){
			var info = s_info[i];
			if(town_info[info[3]] == null){
				town_info[info[3]] = info[3];
				townElement.options[cnt] = new Option(info[3], info[3]);
				cnt++;
			}
		}
	}
	
	deleteSchool();
	var schoolElement = document.getElementById('name');
	schoolElement.options[0] = new Option("選択してください", "");
 	cnt = 1;
	if(s_info.length > 0){
		for(i = 0; i < s_info.length; i++){
			var info = s_info[i];
			schoolElement.options[cnt] = new Option(info[0], info[1]);
			cnt++;
		}
	}

}

function viewAllSchool(){
	var souken = school_info[0];
	var brain  = school_info[1];
	var piazza = school_info[2];
	var klc    = school_info[3];
	var nameElement = document.getElementById('name');
	if(nameElement > 0){
		var len = nameElement.length;
		for(i = 0; i < len; i++){
			nameElement.options[len - i] = null;
		}
	}
	var cnt = 0;
	nameElement.options[cnt] = new Option("選択してください", "");
	cnt++;
	if(school_info.length > 0){
		for(i = 0; i < school_info.length; i++){
			if(school_info[i].length > 0){
				for(j = 0; j < school_info[i].length; j++){
					nameElement.options[cnt] = new Option(school_info[i][j][0], school_info[i][j][1]);
					cnt++;
				}
			}
		} 
	}
}

function jumpURL(){
	var nameElement = document.getElementById('name');
	if(nameElement.value != ""){
		location.href=nameElement.value;
	}
	return false;
}

function selectPref(){
	var prefValue = document.getElementById('pref').value;
	var id = 0;
	for(i = 0; i <document.form1.type.length; i++){
		if(document.form1.type[i].checked){
			id = document.form1.type[i].value;
		}
	}
	if(id > 0 && prefValue != ""){
		var s_info = school_info[id - 1];
		deleteTown();
		var townElement = document.getElementById('town');
		townElement.options[0] = new Option("選択してください", ""); 
		deleteSchool();
		var schoolElement = document.getElementById('name');
		schoolElement.options[0] = new Option("選択してください", "");
		var cnt = 1;
		var s_cnt = 1;
		if(s_info.length > 0){
			var towninfo = new Array(s_info.length);
			for(i = 0; i < s_info.length; i++){
				if(prefValue == s_info[i][2]){
					if(towninfo[s_info[i][3]] == null){
						towninfo[s_info[i][3]] = s_info[i][3];
						townElement.options[cnt] = new Option(s_info[i][3], s_info[i][3]);
						cnt++;
					}
					schoolElement.options[s_cnt] = new Option(s_info[i][0], s_info[i][1]);
					s_cnt++;
				}
			}
		}
	}
}

function selectTown(){
	var townValue = document.getElementById('town').value;
	var id = 0;
	for(i = 0; i <document.form1.type.length; i++){
		if(document.form1.type[i].checked){
			id = document.form1.type[i].value;
		}
	}
	if(id > 0 && townValue != ""){
		var s_info = school_info[id - 1];
		deleteSchool();
		var schoolElement = document.getElementById('name');
		schoolElement.options[0] = new Option("選択してください", "");
		var cnt = 1;
		if(s_info.length > 0){
			for(i = 0; i < s_info.length; i++){
				if(townValue == s_info[i][3]){
					schoolElement.options[cnt] = new Option(s_info[i][0], s_info[i][1]);
					cnt++;
				}
			}
		}
	}
}