Strange behaviour on Safari when trying to submit form using iframe

Hi All,

Not sure if this is the correct forum to raise this question

I am using iframe based mechanism to submit my login from and it is working fine on each and every browser except Safari.Here is the HTML form I am using to submit the information

<iframe height="0" width="0"  name="loginFrame" hidden="true"> </iframe>
<form:form action="${loginActionUrl}" method="post" commandName="loginForm" id="header-signin" target="loginFrame" name="header-signin">
  <input type="text"   name="j_username" id="header-signin_j_username"> 
  <input type="password" name="j_password" id="header-signin_j_password"> 
  <input type="button" class="btn1" value="Sign In" id="login" formnovalidate="formnovalidate"/>
</form:form>

and here is the java-script code

$(document).ready(function(){
$("#login").live('click',function(e) {
      if(validateSigninForm('header-signin')){
          $("#header-signin").submit();
     }
     });
});

there are some additional JS code which is being used

if($('#header-signin_j_password').length){
    document.getElementById('header-signin_j_password').onkeydown = function(event) {
        if (event.keyCode == 13) {
         triggerSigin(this.form.id);
       }
    }
}

triggerSignin is simple using Jquery submit method to submit the form.

When I fill the password filed and press the enter button, everything is working fine and page is getting refreshed with the help of the iFrame, but if I click on the sing in button, Safari is opening a new browser window and sending null values to the back end server.

This behavior is only noticeable for the first time and if I click on the signin button second time, It will be working perfectly fine till I close the browser and open it again.

I am not sure what is going wrong here and this approach is working fine on all other browsers.

Can any one help me in this?