fix limitless loop when error password

if(document.URL.indexOf("https://cas.sustc.edu.cn/cas/login") >= 0 )   

{

	chrome.runtime.sendMessage({storage: "all"}, function(response) {

		var user = response.username;

		var pass = response.password;

		var auto = response.auto;

		if(auto=='true'){

		if(document.getElementById('msg')==null){

			if(response.auto=='true'){

				document.getElementById('username').value = response.username;

				document.getElementById('password').value = response.password;

				document.getElementsByName('submit')[0].click();

			}

		}

		else{

			if(document.getElementById('msg').getAttribute('class')=='errors'&&response.auto=='true'){

				document.getElementById('msg').innerText = '用户名密码错误！请在插件中更新信息并从地址栏刷新页面';

			}

		}

	});

} else if(document.URL.indexOf("http://enet.10000.gd.cn:10001/sz/sz112/transfer.jsp") >= 0 ) {

	document.getElementsByTagName('input')[0].click();

		</tr>

		<tr>

			<td><button type="button" id="change">Save</button></td>

			<td id="ok" style="display:none;">OK<td>

			<td id="ok" style="display:none;">Saved<td>

		</tr>

	</table> 

		<input type="checkbox" id="auto">Enable auto login</input>