function init(){
	if(getCookie("username")!="") document.getElementById("username").value = getCookie("username");
}
function checkLogin(){
	if(trim(document.getElementById('username').value)==""){
		alert('请输入帐户名称！');
		document.getElementById('username').focus();
		return false;
	}
	if(trim(document.getElementById('password').value)==""){
		alert('请输入帐户密码！');
		document.getElementById('password').focus();
		return false;
	}
	return true;
}
function trim(str){ //删除左右两端的空格
	return str.replace(/(^\s*)|(\s*$)/g, "");
}