I have jsp page with method = POST and action='/mydir/mypage/nextpage'

I have a button :

< button title='Continue' onclick="this.form.perform.value='cancelButton'; javascript:doCloseWindow();" >Continue < /button >

and java script method like:

function doCloseWindow(){
location.href = "https://abc.xyz.com/mydir/?param=123";
}

It does not work in fire fox 3.6. On click of button; it redirects to the path I mentioned in form action.

With Tamper data I find that the request goes to URL ( as in method ) with GET and then it re-directs to form's action URL.

I added return false in the method call also.-- javascript:doCloseWindow();return false"

I tired various combination like

window.location.href = "https://abc.xyz.com/mydir/?param=123";
window.document.location.href = "https://abc.xyz.com/mydir/?param=123";
document.location.href = "https://abc.xyz.com/mydir/?param=123";

But no success.