Javascript Console Commands Not Working After Ajax Sending Back in Page

I'm controing a website on chrome developer console. There are a form and a submit button for sending form with ajax (I guess) without refresing the page. The form is reseting after sending informations.

I just assign some attributes to a form element in page with javascript. There are some processes that isn't matter, and I'm sending the form but the attributes on elements are reseting in the new coming form. I've force into calling same scripts again.

Is there anyway for global valid command with console coding, because the webpage isn't mine? (In pure-JavaScript)