Browser crashes when using jquery's $.post ()

Code:

functionVerifystepone () {varPhoneNumber = $ ("#phoneNumber"); varUsername = $ ("#username"); varPassword = $ ("#password"); varVerifycode = $ ("#verifyCode"); varErrorInfo = $ ("#errorInfo"); if(!Phonenumber.val ()) {errorinfo.html (' Mobile phone number cannot be empty! '); return; }    if(!Username.val ()) {errorinfo.html (' User name cannot be empty! '); return; }    if(!Password.val ()) {errorinfo.html (' The password cannot be empty! '); return; }    if(!Verifycode.val ()) {errorinfo.html (' Verification code cannot be empty! '); return; } errorinfo.html (‘‘); varurl = $ ("#url"). html (); URL+ = '/do/doaction.html '; $.post (Url,{registerflag:' Registerstepone ', PhoneNumber:phoneNumber.val (), Username:username.val (), Password:password.val (), Verifycode:verifycode}, function(data,status) {if(Status = = ' Success ')){            //Console.log (data.msg);Alert (' Hhe '); }    },' JSON ');}

Why does the browser crash?

functionVerifystepone () {varPhoneNumber = $ ("#phoneNumber"); varUsername = $ ("#username"); varPassword = $ ("#password"); varVerifycode = $ ("#verifyCode"); varErrorInfo = $ ("#errorInfo"); if(!Phonenumber.val ()) {errorinfo.html (' Mobile phone number cannot be empty! '); return; }    if(!Username.val ()) {errorinfo.html (' User name cannot be empty! '); return; }    if(!Password.val ()) {errorinfo.html (' The password cannot be empty! '); return; }    if(!Verifycode.val ()) {errorinfo.html (' Verification code cannot be empty! '); return; } errorinfo.html (‘‘); varurl = $ ("#url"). html (); URL+ = '/do/doaction.html '; $.post (Url,{registerflag:' Registerstepone ', PhoneNumber:phoneNumber.val (), Username:username.val (), Password:password.val (),Verifycode:verifycode },        function(data,status) {if(Status = = ' Success ')){            //Console.log (data.msg);Alert (' Hhe '); }    },' JSON ');}

The red code passes an object, so there is an error, and the $.post () cannot pass the object? Haven't found the answer ...

Browser crashes when using jquery's $.post ()