//ドロップダウンメニュー：dropdownMenuの引数は2個ずつセットで（n+1番目の引数はリンク先URL、n+2番目はページ名）
function dropdownLink() {
	location.href = document.dropdown.selectpages.options[document.dropdown.selectpages.selectedIndex].value;
}
function dropdownMenu() {
	document.write('<form name="dropdown"><select name="selectpages" onChange="dropdownLink()">');
	var myArg = dropdownMenu.arguments;
	for (i = 0; i < myArg.length-1; i+=2) {
		var myURL = myArg[i];
		var myLINK = myArg[i+1];
		var mySelected = location.href.indexOf(myURL)>0 ? " selected":"";
    	document.write('<option'+ mySelected + ' value="' + myURL + '">' + myLINK + '</option>');
	}
	document.write('</select></form>');
}