Wait for change in page to continue the script

[Renan Amorim (Ren)]

Hello, i have developed a script to fill a form in a website in my work, but when filling the form i have to wait for the site to upload. I am doing this with the sleep fuction, so I fix a timer to wait and then the script continues. It’s possible to change from waiting a fixed time to wait for the site to upload?

Example: I fill my work number, then the website uploads my fullname, after that i have to continue filling other parts