Ask for help, JS method called the problem, write the return value, make sure to return undefined when the call (new first write)

text box txtUserName ONBULR binding method Txtusernameonblur This can be performed normally

The Click event for the following Btnregister does not call Txtusernameonblur () properly

Do not know is not AJAX callback function call problem, help

$ ("#txtUserName"). Bind ("blur", Txtusernameonblur), function Txtusernameonblur () {if ($ ("#txtUserName"). val ()! = "") { $.post (".. /.. /myashx/checkregister.ashx ", {" txtUserName ": $ (" #txtUserName "). Val ()," Checktype ":" Checkusername "}, Function (                Result) {if (result = = "Notexist") {$ ("#msgUserName"). Removeclass ("errormsg");                $ ("#msgUserName"). AddClass ("successmsg");                $ ("#msgUserName"). Text ("√");            return true;                } else if (result = = "Exist") {$ ("#msgUserName"). Removeclass ("successmsg");                $ ("#msgUserName"). AddClass ("errormsg");                $ ("#msgUserName"). Text ("X");                Showheadermsg ("ErrorMsg", "successmsg", "User name already exists");              return false;    }        });        } else {//user name is empty!        $ ("#msgUserName"). Text ("X");        $ ("#msgUserName"). Removeclass ("successmsg");        $ ("#msgUserName"). AddClass ("errormsg");        return false;    }}$ ("#btnRegister"). Click (function () {if (Txtusernameonblur ()) {//undefined 
} else {showfootererrormsg ("* The above information is incorrect, please complete the registration information *"); }});

　　

Ask for help, JS method called the problem, write the return value, make sure to return undefined when the call (new first write)