How to get the last waterfall view?--Chinese engineer for help!!

I have a page which need to simulate user login before,so I write a script as below:

setDns name=TPL_username tmallb302setValue name=TPL_password taobao1234submitForm id=J_StaticForm navigate

But the waterfall picture in the result contains three pages’ full waterfall image, how can I get the only page’s waterfall img which I want, in other word, how can I get the last page’s waterfall image?

My English is very poor and sorry for that.

You can use logData 0 to turn off logging and then logData 1 before the step you want to capture the timings for