function SelectCss(dir){
/* set variable */
var pas=dir;
var cssDir = 'css/';
var cssTags = '<link rel="stylesheet" type="text/css" href="';
var flag = null;
var _agent2 = navigator.userAgent;

/* css deverge for cross platform & cross browser */
if (_win) { // win os
	if (_ns6up || _moz) { // win_ns 6.x or mozilla
		flag = 'win_ns6x';
		document.open();
		document.write(cssTags +pas+ cssDir + flag + '.css" title="WinNS6x_CSS">');
		document.close();
	}
	else if (_ns4 || _ns4up || _nav4) { // win_ns 4.x
		flag = 'win_ns';
		document.open();
		document.write(cssTags +pas+ cssDir + flag + '.css" title="WinNS_CSS">');
		document.close();
	}
	else if (_ie4 || _ie4up || _ie5 || _ie5up) { // win_ie
		flag = 'win_ie';
		document.open();
		document.write(cssTags +pas+ cssDir + flag + '.css" title="WinIE_CSS">');
		document.close();
	}
	else if (_ns2 || _ns3 || _ie3) { // win no support browser
		flag = 'win_ns';
		document.open();
		document.write(cssTags +pas+ cssDir + flag + '.css" title="WinNS_CSS">');
		document.close();
	}
	else if (_opera) {
		flag = 'win_ie';
		document.open();
		document.write(cssTags +pas+ cssDir + flag + '.css" title="WinOpera_CSS">');
		document.close();
	}
	else {
    top.location.href = pas+'requirements/index.html';
	}
}

else if (_mac) { // mac os
	if (_ns6up || _moz) { // mac_ns 6.x or mozilla
		flag = 'mac_ns6x';
		document.open();
		document.write(cssTags +pas+ cssDir + flag + '.css" title="MacNS6x_CSS">');
		document.close();
	}
	else if (_ns4 || _ns4up || _nav4) { // mac_ns 4.x
		flag = 'mac_ns';
		document.open();
		document.write(cssTags +pas+cssDir + flag + '.css" title="MacNS_CSS">');
		document.close();
	}
	else if (_ie4 || _ie4up || _ie5 || _ie5up) { // mac_ie
		flag = 'mac_ie';
		document.open();
		document.write(cssTags +pas+ cssDir + flag + '.css" title="MacIE_CSS">');
		document.close();
	}
	else if (_ns2 || _ns3 || _ie3) { // mac no support browser
    top.location.href = pas+'requirements/index.html';
	}
	else if (_opera) {
		flag = 'mac_ie';
		document.open();
		document.write(cssTags +pas+ cssDir + flag + '.css" title="MacOpera_CSS">');
		document.close();
	}

	else {
    top.location.href = pas+'requirements/index.html';
	}
}

else {
	flag = 'This site no support your platform...';
    alert(flag);
}
}