[JavaScript] URLパラメータ取得

gistfile1.js

function getParameter(key) {
	var str = location.search.split("?");
	if (str.length < 2) {
		return "";
	}
	
	var params = str[1].split("&");
	for (var i = 0; i < params.length; i++) {
		var keyVal = params[i].split("=");
		if (keyVal[0] == key && keyVal.length == 2) {
			return decodeURIComponent(keyVal[1]);
		}
	}
	return "";
}