function checkForm(){
if (form1.userName.value ==""){
		alert("请输入用户名称！");
		form1.userName.focus();
		return false;}
if (form1.password.value ==""){
			alert("请输入用户密码！");
			form1.password.focus();
			return false;}
return true;
}
function showBar()
{
	if(leftBar.style.display=='none')
	{
		leftBar.style.display="";
		show_hide.src="images/show-hide.gif";  //myText.innerText="隐藏导航菜单";
	}
	else
	{
		leftBar.style.display="none";
		show_hide.src="images/show-hide.gif";   //myText.innerText="显示导航菜单";				
	}
}