function checklogin(){
		if (document.login_Form.username.value==""){
			alert("请输入用户名");
			document.login_Form.username.focus();
			return false;
		}
		if (document.login_Form.password.value==""){
			alert("请输入密码");
			document.login_Form.password.focus();
			return false;
		}		
	}