help me please

hi everyone ive got a hp chromebook im not clued up on computers but i can get by ive recently got a samsung s4 mini and the first time i activated the mobile tethering it asked me for the password and i could use my phone s internet but when i shut down and log on to it the next day it connects to my hotspot but it doesnt allow me to surf the net because it doesnt give me the option of entering the password again can any one help please thanks