Assuming the $.click() actually worked, you need to wait until the page has loaded.
setTimeout:
You may feel lucky and try it with
page.evaluate(function() {
// form vals and click
});
setTimeout(function(){
page.render('example.png');
phantom.exit();
}, 3000); // 3 sec timeout
waitFor selector:
You may use the waitFor example from the phantomjs package to wait for an element that you know is only on the loaded page, but not on the current page.
waitFor loadFinished:
You may combine waitFor with the onLoadFinished callback handler to do wait for the next page to load. This is preferable since this would work every time and would not impose overshooting with a conservative timeout.
Just use CasperJS:
Nothing more to add.
