Salesforce VisualForce 使用apex:actionFunction调用后台方法

<apex:inputHidden id="flag" value="{!flag}"/> <apex:actionFunction action="{!searchCon}" name="searchCon1" oncomplete="return savemessage()" reRender="form1"> <apex:param name="uname" assignto="{!username}" value=""/> <apex:param name="pword" assignto="{!password}" value=""/> </apex:actionFunction>  function savemessage()  {                if(document.getElementById("page:form1:flag").value == "false"){                 alert("用户名密码错误...